best one I have done so far is a 2DIN Eonon unit - cost was roughly $350 to the door. full reverse camera, GPS, dvd, tv and the rest of the gizmo's. easy as to install, just need and aearial adapter and aerpro wiring harness and can install from scratch in around 30 mins
I have put several different ones in from no-names and to brand names etc and these are by far the best without breaking the bank. They come with Sygic maps but you run any that use WinCE systems which covers memory maps and Oziexplorer as well