I also plan on getting rid of the 6x9s and get real good speakers up front, Any good ideas on this
That's definitely a step in the right direction. A rear fill, in my opinion, is worthless. Music is recorded in stereo. It's meant to be listened to in stereo. A rear fill detracts from what the artists and producers published. Check around on DIYMA and read some reviews on good 6.5" components. I'm running the Pioneer Premier TS-C720PRS components in the Caprice. They don't make them anymore, otherwise I'd recommend them. They easily compare to my buddy's Hertz Milles but I paid half what he did.
-94 Caprice Classic LS - system, Gary's wires, 200 amp alt, tint, first base/home plate delete, clear corners w/green parking lights, LTZ hood emblem, SS springs
-97 Grand Cherokee TSi - 4" IRO lift, OEM skids/hooks/hitch, sliders, 31s, rear locker, system, tint, cloth, clear corners, Magnaflow stuff
Refs: DesertDawg, 214Texas, QUICKSSILVER, SSon22s, MadMav, gary burton