2001 Ford Taurus SEL Upgrades??

I have a 2001 ford Taurus SEL, (200HP Duratec 24v DOHC) and was wondering if there are any upgrades I can get for the engine or transmission? I had a few parts in mind but if there is anything else then I'd appreciate the imput. I was thinking about a Chip (any particular chips that work good with the Duratec Engines? Price does not matter). Does K+N make a filter for this car? Would I be able to put Airbags on the car so I can have it lowered but still be able to raise it about 4" to clear some things (steep driveway here in memphis). Anyone make a supercharger or turbo for this engine? I'm trying to keep the outside as stock as possible, so it's somewhat undercover, the only thing I'll be doing aesthetically is (besides the tinted windows) is getting the rims painted flat black, and lowering the whole car. Oh and sundance headlight flashers.
Thanks for any advice or tips I really appreciate it, there aren't many places that have any info about upgrading this model car, but This place looks like a great place to get started.

Kermit