Any advice on new speakers for my 02' F150 reg.cab? Just installed Sirius radio(direct wire) and would just like to upgrade the stock speakers for some improvement on sound.....any mid range speakers, +/- $100., impress right now as of Jan. 07' that the stock HU can push enough to improve the sound? I've read here that Infinity are nice.....which model #?

Infinity Reference 6812cf
or
Infinity Kappa 6827cf
or
Infinity Reference 6810cs

thanks