Summer minimalist carry and extra layers.

[TreeChopper]

I'm very interested in the light weight merino wool long sleeves as well. I bet they may be a bit more thermoregulatory than the poly pro. I'm terribly rough on my gear though so I'm on the fence about buying one.

Try GoodWill... it's been stuffed with wool items all winter and still is. I got a SmartWool sweater for $5 and love the thing. Every week a different color tag is 50% off plus the website usually has a 10% coupon you can print out.
If you hate or destroy what you bought there, you haven't wasted much money.