Wood is probably not the best choice for a counter with a sink but it's for me and I'm going to try it anyway. My species of choice is antique heart pine. The sink will be a full size double bowl under-mount that's meant for granite. For the top I will build up (or double) the edges of 3/4 material to give an 1 1/2" thickness. At the bowl however, I will leave it 3/4 and mount the sink directly to the underside of the top letting the wooden edge overhang the bowl by 1/2" or so (similar to granite applications). I will silicone this joint between stainless and wood quite well.

So for a finish I've thought of everything from WaterLox to Boos to Poly, but I'm not sure which will hold up to water the best. I will be building the top with quarter-sawn lumber and along with it's already resin-ous nature, I'd think it'll be pretty waterproof already. But I'm sure some moisture invasion is going to be inevitable. Thoughts?