Yeah what tony said...

I'm actually driving a '01 tahoe around for the next week or two as I learn to drive with a trailer, and while the sound system is pretty good, it's nothing to worry about replacing. A decent amp will run you less than the cost of the alpine, and far less than the cost of the CD changer. Alpine is good stuff, but it isn't cheap. If you want CD's, get a cheaper CD player and have it feed into the empeg. You won't use it enough to justify spending much on it.

The alpine deck is unnecessary... If you were happy with the factory stereo, I'd call crutchfield and see if they've got an adapter that will let you plug something into the factory stereo. If that still has ground loop problems, go over the FAQ's ground loop trouble shooting. If you want to replace it, buy an amp and do it right. It won't fit in the dash quite right, but you can find a trim ring for it I'm sure...

Good Luck,
Matthew