Give Icebreaker merino wool a try, I have used it and find it to be itchy only before it is first washed. Very comfortable and lasts much longer than any sitka gear. As suggested wool for a base layer is an excellent choice, then your camo on top. Icebreaker offers many different weights to choose from. I currently use the lightest weight and find it usable in heat as high as 85-90 degrees (obviously with no jacket or shirt on top of it).
