only wah that I own/have ever played was on my multi-effects board... but, the most popular wah seems to be the dunlop crybaby wah... the 535Q (the one I'm looking at getting sometime soon) has a knob on it to switch between 6 (i think it was 6) different kinds of wah to suit all styles. my be worth looking into.
some reviews on the dunlop crybaby 535Q