For bamboo, I think Crystal Palace can't be beat.
The new Harmony needles at knitpicks are wonderful-- very, very smooth. They do seem to have had some manufacturing problems, but if you have splintering or other such stuff, they do replace them immediately.
For exotic woods, try www.winterrose.com
I do prefer the coated grey metal needles for many things, but also bone and glass are great once you get used to them-- is there a reason you specifically want to use wooden needles?