I want to put a touchscreen in my car that has gps, radio and cd changer.?

I want to put a touchscreen in my old mercedes because every speaker is blown and I'm gonna be in there anyways. I don't want to be installing a whole computer system though. I just want something that would have gps, control over a cd changer, be able to tune into AM/FM radio, and use a aux jack for my ipod. Basically everything that you would get in the newer luxurary cars. I don't want to install a PC but if thats gonna be my only option I guess I will.