Just some thoughts that come to mind:

* I also have a seperate head unit in addition to the empeg, and am glad I do. I run the empeg into it's Aux input and use it 90% of the time. I do use the CD player as well - occasionally if I know I will be somewhere, such as downtown where I must park overnight, I just leave the empeg at home, and can still listen to music. Also on the very cold winter days here (MInneapolis) I leave it at home instead of abusing it in the weather. And when it's broken (like now), I still have music. Not to mention how much cheaper it was than buying a tuner kit.

* I have this deck: http://sm.crutchfield.com/S-SZKhsWMAXMG/cgi-bin/ProdView.asp?s=45&c=3&g=62700&I=158F7700&o=p&a=0&cc=01&avf=N&search= (sorry for the ugly link) and am pretty happy with it. I like the looks, it has my aux input, and when you turn the graphics off and information on, the display is nice as well. One idea for you...

* Make sure you listen to your speakers before buying. In the store / vs in the car will be different, but it will be a start. Don't purchase anything you haven't heard. Also, I'd focus on good front speakers, and don't worry much about the rears. My theory is that you should barely be able to hear them, that almost all sound should come from in front of you. I also recommend a sub, just to fill in the music. You don't need to listen to rap to get use of a sub. A single 10" would suffice, it doesn't need to be a "wall of woofers".

Hope that helps some. Also - don't forget to get a good quality fuse setup near the battery for any cables you run! Expect to spend $100 or more just for wires and patchcords on top of any other components you buy.