If you are talking under-layers, any poly and fleece is fine I'm not brand loyal. And I don't find the high-end stuff worth the extra money. I do like Under Armour long tees and Long John's though. If you buy them online they're about half of retail price.
In the climate I hunt in I really like the Helly Hansen impertech rain gear, and it doesn't need to be the camo version either, they're OD green Works in about any application.

^^^^^^
I should mention that with the combination I use, you will get wet from condensation when you exert yourself. Where I hunt though it's better to be wet underneath but wind-proof on the outside. If/when I get damp, I will strip down to my under armour and usually I will dry out in just a few minutes, especially if there is any sort of a breeze.
Staying warm and dry is a science if not an artform.

AJE
These northern trapper/hunter fellas are giving you good advice on clothing, but I think you need to realize the differences between their activities and yours.
For these guys, other than long boat rides on a river or maybe a couple hour glassing sequence, I think it is a rare occasion that they sit in one spot for hours on end like we do. I don't want to take anything away from these guys and most of them experience way lower temps then we do at times but there is a huge difference when your doing any kind of physical activity in the cold or just sitting in one spot for hours on end.

I am like you, as I spend a lot of time sitting/swaying 20 ft up in a tree.
If you are a bow hunter like I am, last fall, particularily during rut was dang cold.
There are 3 things that I would recommend to you to help you keep warm.
1) As the guys above stated, lots of good gear with wool or fleece out there. Whatever you choose, try to find something with a wind stopper membrane in it. I have a parka & bibs set. fleece layer inside,wind stopper and thinsulate middle and fleece outside. had it for 20+ years and works very well. I don't usually bring it out till the temps are in the single digits and the wind will be up. And i by all means never wear this stuff on the walk in.
2) On walk ins, make sure your top base layer is something long sleeved and cotton as you want it to soak up all your sweat on the way in. Once your at your stand, you strip down to the skin, use the sweaty T as a towel and dry yourself off as best as you can.
I usually keep my shirt off as I prepare my gear for my ascent and let any breeze there is dry me off. If you've never done this, you'd be surprised how fast you'll dry. I usually have a UA long sleeve T in a bread bag that I pull out and put on. I turn the bread bag inside out and stuff the sweaty T in it. I do this almost all the time unless I have a really short walk.
3) Never eat breakfast... But bring lots of food...
A big breakfast will just add to profuse sweating on walk ins and just make it miserable because half way to your stand you'll probably have to poop.
Another thing not eating breakfast does is, right about the time you're all settled in and cooled down, you'll be staring to get hungry. I usually wait an hr or so but not to long and I'm eating something already. I space out my eating through out the day so as to always keep the calorie intake up. For me it makes a huge difference between being able to make it for an 11 hr sit or not.

Not trying to sound like a know it all just saying what works me..

My hunting buddy gets cold all the time. He purchased a Heater Body suit and he can now stay in a stand all day.

Oh, now I see what you guys are talking about.
Get some bunny boots for your feet, and a fur hat for your head, that will keep both ends of you warm which will help immensely keeping the middle of you warm.

Thank you, very helpful

Sitting in a stand, I wouldn’t spend the money on it.
You can get down pants, a down coat, better base layers, handwarmers, better boots, heated vests.


Your first mistake is asking trappers, the cheapest people on the planet, the Hebrews of outdoor recreation, about $600 jackets.


I have a completely different experience with Sitka gear than the others here.
It has never failed me, the patterns are amazing, I’ve never been closer to game, had game not spook, and had goats walk to within touching distance.
I’m convinced the patterns can’t be beat.

I also have their storm front rain gear, frankly, I own almost every product they make.

There are a couple of pieces which are just ok... but the majority of it, I am impressed with, and have had zero issues with the quality.

I have used the same outfit for 4 years now on 20+ hunts, sheep, multiple goats, kodiak, PwS, bear hunting, caribou, moose, from Nome to Illinois, and it is still not only useable, but in great condition.

My Storm front raingear I have been in south east with 7” of rain and 50-85mph winds in 6 days, hunted and hiked up and down the brush in Kodiak with it, it has always kept me dry, itslightwr than my Helly and it’ll dry out on the inside,unlike the helly Hansen.
It’s expensive, not everyone has $1,200 for rain gear. It’s the same price as the other 3 layer gore Tex pro gear by ArcTeryx, Black Diamond, Etc. The lighter and cheaper rain gear isn’t as durable, or tough, but it’s lighter, and cheaper, and what most people buy... for those reasons.

There are trade offs to make, cost, effectiveness, weight.
It can be good, it can be light, it can be cheap, but it can’t be all three..

I’m not a fan of Kuiu mainly because the owner was a complete douche of a human. I refuse to support someone like that. And it’s not as good as Sitka, the camp patterns are trash, especially the Vias.
Except their socks, they make the absolute best socks, hands down.

I usually lump the “it’s overpriced yuppie gear, just wear carharts and a woolrich coat” people in with the “Vortex scopes and binos are just as good as Swarovski for the money” crowd. To summarize this statement, most people don’t have the right to opine because they don’t have the money to buy the most expensive, or best gear, to compare it to the “just as good” stuff they can afford.

Can you kill stuff in blue jeans and red cotton button up shirts? You bet.
I’m sure waterrat and Pete can blow most people’s minds with photos of animals killed or guided dressed like a Los anchorage hobo, lol....

But I guarantee you, they weren’t as comfortable, and don’t look as good as me in my Sitka gear.

Waterrat and I look better than you in WHATEVER WE WEAR.....! We are the epitome of comfort and paragons of sartorial virtue! We cannot help it.

Pete

Hup:

I thought the owner of SItka gear sold the company - then after the no compete period, started Kuiu gear. Bad rumor ?

The guy was known to SE Alaska guides - Kuiu Island being across from Baranof Island where SItka is located.

Harriston was one of the founders of Sitka gear, and they got hired by Sitka and he was fired.

After the no compete, he did start Kuiu without the top brand names in goretex and primaloft and just continually trashed Sitka while making inferior products.

There’s a lot of stories out there and his own words which can be looked up to see what an arse of a person he was. And one who used helicopters for sheep hunting, was a jackoff about women hunting, and projected his arrogance like it was an attribute for people to look up to.

I would not recommend the Sitka rain jacket. I have owned two.