which one? there is one that looks like a stock single piston unit but has a bigger bore, and there are 2 and 4 piston calipers that bolt to the stock brackets and (i think) use the stock pads..
the single piston calipers won't take up any more room than the stockers, and the multi piston units might take up a little bit nore room.. but the stock rotors are so small that i don't think you'll have any problems with any wheels that are bigger than 14" in diameter.