He said he's putting a Sony aftermarket unit in the dash. That could as easily be an empeg,

Okay, if that's the case, then I totally don't get it.

RobsM3, the empeg is so much better than the music keg, you have no idea what you're giving up. If you're able to put a DIN-sized unit in your dash (such as the Sony), and you already have an empeg in your possession, then just install an amp and do it. Forget the Sony, forget a tuner for now and get the tuner kit in a few weeks.