I may be a little bit late on posting here but I've had, and seen others with sony xplods. To me, they're useless, sound like crap (no offence to ne one that owns them around here..) but I would defiently go with infinity for all of your up front speakers. Also if you don't already have a 4 channel amp for your front speakers i'd advise gettin one. I got 4 Infinity Reference speakers in my car and I must say they sound amazing with this 4 channel alpine amp I got. As far as woofers go, I wouldnt touch sony, but thats me. I'd go with Hifonics, Alpine, or Rockford fosgate for a woofer and same goes with amps. I dont know if you've replaced ones that came with your car but I would advise it if you want best sound quality/loudness.
_________________________
Inferno Package/CAI/180tstat/3" DP/AL 104 XP's/3.8 MPS/Tuned