Do you plan on staying N/A or going FI? That would make a difference as far as the setup of the CAI. The intake runner to the throttle body would have to be longer for the S/C intake. The WMS would not be easily doable for the S/C I believe due to the shape of the air filter. The top performers of CAI would be C&L, JLT, Granatelli and WMS. The C&L and JLT REQUIRE a computer reflash whereas the Granatelli and WMS do not. They will all net you 20+ RWHP. I purchased and just did a self install of the WMS CAI. It by all means is the mot work involved CAI to date. It requires you to relocate your radiator overflow bottle over to where the stock air filter box sat AND to extend the MAF wires by cutting and splicing them. There are 3 main reasons I went with the WMS. #1-Near same power gains as C&L and JLT but doesn' require a retune. #2-With the optional ram air tray(which I also purchased)that has 3 holes above your grill to allow cooler outside air in and forces it right to the filter(works perfect with the stock hood!!!!!). This has to be better than the traditional CAIs as they still get the air that comes up from inside the fenderwell. After removing the stock air filter box I was quite shocked to see how patheticaly small the hole is that feeds the box inlet. #3-The look. It looks so different than any of the others.
A tuner will make a night and day difference as well!!!!! I just got the SCT X-Cal 2 from Brenspeed with his 3 cutom tunes(1 for each octane rating). My automatic is a beast now compared to stock. It will burn the tires now off the start and break loose shifting into 2nd...all with TCS on. With the stock tune it would just chirp 2 or 3 times off the line and shift like a luxury car into 2nd. There is NO throttle lag. Touch the gas pedal and you're on your way. It pulls hard to and through each gear change. It downshifts less now with the incresed power, which makes it great for cruising.