RE: What type of Air Filter should I buy?
Ummm... there is no reason for the MAF to get dirty if you have a good filter on there. Thats part of the reason for a filter.
The oil may or may not contaminate the wires. The reason for the oil causing the problem would probably be an over-oiling of the K&N after cleaning.
The reason i won't use a K&N filter is that they filter like crap. I had my oil analyzed with a K&N filter on the car, and the only thing they found was excessive solid particles, that were not metal, and could only have come through the air filter.
Also, I have a friend that works for Wix, and he benchmarked a K&N filter at one time. He said something about having to completely disassemble the test machine afterward because the filter let so much crap through. I'm not sure exactly what he was talking about, but he said they're crap. But that should be no surprise. There are giant holes in the filter, that you can SEE through. Dirt is going to get in. For my money, i'll buy a filter that filters, thank you very much.
As far as a cone filter goes, i picked up an '02 GT airbox. It has a stock paper cone filter. The airbox has the same bolt pattern as out MAF, but you have to cut down the little studs it screws into to make it seal, and you'll probably have to do some kind of custom work with your hose. Or you can just go buy a paper filter for an '02 Mustang GT and try to make it work. I knocked a tenth or so off my quarter mile time by changing my airbox, according to my Tazzo.