Before modding be sure you do a full tune-up so the mods will add power rather than get you somewhat close performance-wise to where you would be with a tuned up bone stock car.
Tune-up should consist of:
Spark Plugs (can do NGK TR-55'* as they are a good plug for a stock or lightly modded car)
Spark Plug wires (might as well get the good ones right away -I suggest Belden Premium Blue wires from NAPA)
clean the throttle body
Then do the 180* t-stat, CAI and start your exhaust work.
Team up the ported manifolds with rockers and this high flow cat and you will have a noticable gain in power (not supercar power, but enough to make you smile). The tuneup and these mods would probably net you another 20-25 hp, and probably a 15.5 -15.7'ish 1/4 mile.