I think it will look as good in walnut as anything. Walnut is a tad softer than maple, so shaping may be a little easier.

Also, with 2000bf to choose from, you'll be able to really choose appropriate grain for your rear legs, seat, crest, and spindles. THAT's what'll really make it look good and perform well.

I also highly recommend Waterlox Original Sealer Finish on this. It's easy to apply, has a great color that makes the walnut look dark and rich. It's also about as durable as wiping varnishes get.