New tweeters for '01 Mustang

I wanted to replace the small door tweeters in my '01 Cobra coupe that sit in the speaker pod, opposite the mirrors. I was wondering if anyone has done this and what kind of speakers they reccommend. I was hoping to get something better than your basic $50 speaker, but wasn't sure what. Also, did you hook them up to the factory amplifier that came with the Mach 460 system, or did you use a separate amp? Thanks!

All I want out of new tweeters are crisper and clearer highs. I added a pair of 12" Kicker Comp subs to my trunk about 6 months and they sound great. I figured that the tweeters would balance out the system quite nicely. Looking around on the web, I saw that these are 2.5" speakers, and my guess is that a regular 3" speaker won't work. My other option would be to get a component set-up, but then I would have to replace the lower door speaker and start running into power and crossover problems with the factory Mach 460 amps. Will the factory wiring provide enough power to the small tweeters, or will they be drown out by everything else? What size did you use?