Some of you may not have heard of a New Zealand company called "Icebreaker". They make an excellent range of superfine merino garments (mostly skin- or mid-layers) in just about any style you might need, and at quite reasonable prices. While the range of colours is a little limited, the fabric is so soft and light that you would swear it's T-shirt cotton rather than wool.
I mention it because I have found that a close-fitting garment of fine wool is not only warm in winter, but cool in summer as well

Nil bastardo carborundum
Mark T