For the modder on a budget, the K&N Drop ins and Z1 MAF tubes are a great investment. High gains/$$. Granted they won't be
quite the same as say Injens or GIII's, but if you can't afford those, and don't want to wait/save. You won't go wrong with the more cost effective setup.
My only concern with the AEM's is the "MAF trickery" they do. I know some people on here have them, and have Zero issues whatsoever. That's all well and good, but it just doesn't sit right with me personally.
With Injens, hydro-lock isn't as big of a problem as it's made out to be. You'd literally have to drive into a river for it to be a Serious problem. If you want that style, but don't want that problem, you can look at the Nism0 intakes. Same design, but with a 2nd filter element mounted inside the engine bay. The downside to the Injens is you have to remove/replace your windshield wash reservoir with their unit.
With the Stillens, people do get uneasy about cutting into their front air dam, but I assure you 10 minutes with a dremel and you're done. It's not that difficult even for the timid.
Other options you can consider are the Akuma and AAM intakes. Both use a similar design and come with 2.75" pipe diameters instead of the 2.5" other use. And are lower cost than the GIII's as well.
Lastly, there is the Takeda/GReddy style which is very similar to the GIII's, but uses a Single filter instead of 2 separate ones.
Several options now, basically it all comes down to whats more important to you? Cost/performance/sound/installation difficulty.
