Like shaunspengler said you will not need a tune, but you'd be happier if you got one. I had a BBK cai, flow masters with a catless H-pipe and some 4:10 gears and it was a lot of fun. I bought a Diablo Sports predator tuner and did the basic 93 octane tune and wow it was a noticable differance. I've been seeing alot of promotion for the Bama tunes, but I dont know much about them. Seems like those tuners change popularity alot. Few years ago everyone talked about Diablo Sports for mustangs.
As everyone else said, you don't need a tune. However, American Muscle has a good combo with the CAI and a Bama Tuner (SCT Xcal3) with free tunes for life. I just bought the 4.10 gear kit and tuner. I'd tell you how it does, but my fuel pump just went out