Off of personal experience, I have had the intake setup that dyaballikl had, the sleeper z intake setup, and the makeshift intake from the autoparts store. The one dyaballikl had pullled in too much air for me and the car had some serios lag under full throttle. When I got the Sleeper z intake, it worked really well, but still had a bit of low end lag (seems to be ideal for MTX75 trannies instead of the CD4E) I'm about to buy one off of ebay becaues the heat that builds up in the back of the engine bay melted one of the brackets. the car ran like crap and I think it actually sucked a couple of peices of plastic into the engine. It doesnt seem like it did anything, but I'm still on my guard because it only happened last week.
I'd say do what you want, but the best CAI for the buck is the focus CAI off ebay. and if you do get the autoparts intake , beware of the breaking brackets.