This Sonic Skin windproof vest is one of the most effective we've tested. A soft shell with full Gore Windstopper membrane is joined using Salomon's Ultrasound Seamless Technology for friction-free seams.
Twin handwarmer pockets have zips for security. Available in sizes S-2XL in black, red/grey and blue/grey. Only downers are the lack of a rear pocket and high price.
It takes a bit of effort to find Salomon MTB stuff in the shops, but the hunt is well worth the effort.