I like the SilverKiss by Catalinbread. I have a Mark I.
I think Mike uses a RAT from time to time and perhaps some type of fuzz pedal (probably vintage), but I'd say work on getting the most out of your amp first.
I've read places that Tom Petty used the Red Llama, but I didn't know Mike Campbell used one. I've also heard that he used a rat (probably a vintage one). I guess there should be a disclaimer and ask as a general Tom Petty and the Heatbreakers tone in a box.
I suppose playing into a Vox-y or tweed-y (blonde tolex maybe?) amp set for a touch of hair and using a drive/boost with a tele or p-90...gretsch or ric...and you're nearly there?