Well, if you already have a Kenwood head unit, then it sort of makes that decision up for you... You could go with a different brand if you wanted, but then you'd be stuck installing one of those RF type ones where it taps into the antennae, and when you want to hear the CD, you'll have to change the radio station to like 85.5 FM. Sorta cheesey if you already have a nice head unit in there...
Also, you might want to consider using that same money on a CD burner for your computer instead. There are benefits and drawbacks to each. Changer: Holds a number of discs, but you may only listen to a few tracks on a CD. So perhaps amongst those 6, 10, or 12 CD, you only listen to maybe 36 songs in total? Depends on your listening habits. Burner: Can make copies of your CDs just in case they get stolen, don't have to carry around 6, 10 or 12 CDs anymore, have all your favorite songs on 1 or 2 discs (depends on how you listen again), but you have to burn CD
"program" that is static, listening to the same set of songs.
The nice thing, of course, would be to get both, someday...
Jon