I paint on wood quite a bit. Your answer depends on what look you are after. If you are looking to paint graphics on the wood, then any paint that is designed for hard surfaces with work fine. I use E'tac, but auto air, wicked, etc... will have good adhesion if you prepare the surface well.
If you want the grain of the wood to show through and want just a tinting type of effect then the very best is HOK Kandies. When I put fades on guitars and want the natural grain of the wood to come through the burst effect, I will only ever use HOK Kandies. I'm sure other solvent based candies would work, but HOK is all I've ever used and I have never had a reason to experiment with anything else.
