I'm in the same exact boat you are. I just bought an 03 GT and after looking at the bolt on i could do..i kinda figured out nitrous was the best bang for the buck. I've search this site and corral and everyone's opinion is different. Obviosly the wet kit is what most recommend but there is an issue with puddling and blowing the intake apart, most so this can be solved by making sure you use a window switch, ect... Another person mentioned that on the dyno he noticed a lean condition when the wet kit first turned on cause it was robbing from the fuel rail. So basically what i got from everything i read was to either use the NOS Nossle kit or the Nitrous Express NXL kit both with direct port injection. So that means spending more like 1400.00 for the kit plus accessories..but its the safest way to go
Good Luck
Joe