I wouldn't bother with the factory junk. I see those amps go bad all the time at my shop. Get yourself a new deck (I prefer kenwood). Get 4 quality new speakers. Speaker size should be 6x8s at all 4 corners. If you want to add some nice bass, then get yourself a 10 inch ported box and a sub about 500 watts rms. This will sound a 1000 times better than the factory stuff.
The thing is though if I'm spending money on my car it'll go into suspension and drivetrain not the stereo :p the only reason I'm bothering with factory stuff is because I have a parts car and it's all 100 percent free to me to do this upgrade.