DLP iss the best choice if you don't want a flat panel set. most of the new DLPs are in 1080p and there cheaper than a same size plasma or lcd. I Have both a DLP and a Plasma both are SAMSUNG which is by far the best brand.
first off I assume you want GPS navagation. Because without GPS it is just a map. So to solve that problem you need a usb GPS antenna.Click Here Also what brand is the screen. Because you can sometimes buy a nav unit for the headunit. Hope this helps :)