Well, I don't listen to the stuff you've just mentioned, but if you are going to buy single pedal effects, buy a delay first, cuz almost every amp has reverb...
I'm not sure about the wah thing you said, but it's probably an Envelop Filter effect, or may be auto-wah ...
Anyway if you are a beginner, get a decent multi-effect pedal, and you'll learn more about effects.