I recently put Eclipse (Fujitsu ten) AVN726EA double DIN units into both my Hilux SR5 and V2 CV8. Both are CD/DVD/AM/FM/reverse camera/GPS. The exciting part is the IPOD connectivity. In the CV8 my mrs simply has an Ipod touch plugged into a cable in the glovebox and she can control all Ipod functions from the touch screen. I have an Iphone4 and its firmware won't work via the cable, but bluetooth audio does and I simply play an album on the Iphone and it works on the stereo. Bluetooth phone (handsfree works well too).
None of that probably bothers or interests you too much, but this unit can be programmed to work with steering wheel controls. So all you need is a box with buttons to replicate steering wheel controls (which are just 3 wires with varying resistances for each button). So you could hide the head unit and use the little box with buttons to control the unit. Buttons would be Volume Up/Down, Mode, Next plus more. If it was me I'd make the unit fit in the console in front of the gearstick, even if you just use a vinyl boot to go around it, or make something more elaborate. This way you could use the reverse camera, GPS etc too. Keep all music on a hidden Ipod. And have the liitle "steering wheel control" box handy to the driver. I'd consider maybe building something about the size of a matchbox that you could velcro to the cigarette lighter head or even mount the buttons in the blank panel that goes over the wiper dwell control spot, or velcro it to that removable panel.