I am looking to get something with an auxillery connector for my Z and instead of replacing the stock CD player I figured it might be easier and cooler anyway to get something that is touch screen, has a jack, handles music, and possibly even a navi.

My friend got one for his eclipse and it was really nice but it was also $600. I'm looking more along the lines of 300-350 maybe?

 

For that price range 300-350, you most likely won't get something with nav. Google this JVC KW-AVX810J or KW-AVX710. Good Luck!

 

I am not 100% sure what you are looking for as the final result. Also not sure what you already know so don't think I am talking down to you. What were you going to power the touch screen with? The only thing that will fit in the navi location is a thin monitor, it is not deep enough for a head unit. I think that 710 suggested is a double din unit.
Anyway, there are a few options on the touch screen but they require separate pieces to provide different functions like ipod, Bluetooth, navigation, DVD, etc. And each of those pieces have to be bought separately.

For that price range its hard to even find a touch screen double din replacement of the factory unit.