I've used their beadboard, very nice.

http://www.vintagewoodworks.com/bb-item.html

Why only 1/4" thick?

I'd be wary that thin stock would have way to much seasonal movement---translating by bulging, warping and twisting.

I want 1/4" because I'm using it as a skin on the end of cabinets, it fits real nicely in to the recess. I looked at Vintage they were my first choice however I'd like the 1/4" stock if possible
thanks