zeppelin is cool.
as Arthur mention, and from what I read, JP never uses a particular effect for all their songs. And note also that he was using gear of yesteryear. For you to duplicate his gear = lots of money
Take your time to try out the stock mainstream pedals first. Proco Rat, Boss OD3, BYOC Shredder/OLCircuits ShredMeister, Ibanez Tubescreamer, MXR Distortion are probably good starting points.