i got a 04 rx8 and i heard that the stock tires sucks like ass man what do you guys think??

which tires you guys use ?
what is the best summer tire for this car??
and where is the best place to tires and wheel?

Stock tires are decent. Not worth it to swap out, just for the sake of swapping tires. Unless you are a serious autocrosser don't swap out the tires until the stock units wear out.

Depends on how much you are willing to spend for Max Performance Summer tires :

Price independent : Michelin Pilot Sport 2, BF Goodrich Comp TA KD's, Bridgestone S03 Pole Positions, Goodyear GS-D3

Price dependent (under $200/tire) : Toyo T1S, Falken Azenis ST 615 (coming out)/ST215, Kumho MX

Look at www.tirerack.com, & I got my Toyos at : www.edgeracing.com