If you only want three or four pedals, I recommend one for a heavy tone, one for a spacey tone, and one for a funk tone.
You already have your fuzz/distortion, you have your heavy rock tone.
I'd get a delay or some sort of modulation for your spacey tone. (try mxr carbon copy, affordable and simple)
And to round it out, get an envelope filter for a funk tone. (again, check out the mxr family of pedals, I use the m82 filter)
The advantage to these are you can get even more tones by having two on at the same time, a lot of different possibilities through pedal combinations.
Good luck, be careful, I predict pedal GAS in your future...
