Do you need flame resistant clothing? Or something that meets OSHA? If not, I swear by under armor and other similar materials. Also go to Cabelas and look at the hunting section for wool. I have some lightweight wool jackets that I use for hunting and they are awesome. Thin enough to not be bulky and they cut the wind from going through you.
Like anything else though, the good stuff can be expensive.
John
"Critics are men who watch a battle from a high place and then come down and shoot the survivors." Ernest Hemingway