Im getting 20x9 in the front, and 20x11 in the rear. In the front im going to go with the 255-30-20's, but my question to you guys is, should i go with a 295-25 michelin PS2 in the rear or a 305-25 pirelli?

It depends on the offset of your rear rims. If it is aggressive offset, you might want to stick with 295. If it is perfect fit/custom make like the Carlsson then they recommend 305. Don't take the word from the manufacture or whoever sell you the rim, talk to someone who has excatly your rim will be the best bet.