cai is pointless. its ricer-technology for the mustang. get a k/n trim or remove silencer. if u really want one, i'd get a steeda. they are sweet. but still pointless.
the K&N filter will only tremendously boost your horsepower if your current fiilter is really dirty and restrictive... otherwise i dont think the difference would be very noticable....
as far as cold air kits, most of the ones i have seen come with their own filter, i know BBKs does. the problem with some cold air kits, true the air coming in is away from the engine and cold, but the pipe is still near the engine, and can heat up