I know this might go against the grain of many "real" wood enthusiasts, but I think Warmoth should offer ebonol fretboards. The material is great stuff, and I've heard from other luthiers that it works a lot like real ebony. It doesn't cost too much, and has a slick feel not found in most woods. The price factor will probably become more of a plus as rare hardwoods become more expensive and hard to find.