Right now, one of the new 'PX5' MTCD units would probably be best.
But the on-board amps do only 45w/channel. Since the 'greatest' programmer of customer ROMs on XDA owns a HOTAUDIO/DESAITA, that would be the best choice if you want to run using his software in the future ("Malansky"). XTRONS also makes some PX5 devices. But most tend to be slightly large in screen size; older 4Runners (mine is Gen4) can't handle a screen more than about 6.2 inches, without sticking out of the dash.
I would probably stay away from the older-tech 'PX3' units, even though the software is now quite mature. Most had only 1 GB memory, and that has become a bit of a problem with my own unit. I would also stay away from Intel-Sofia systems, which are somewhat unique. (Neither PXCB nor PXCD, and mostly sold by carjoying. When they switch motherboards, Joying usually stops doing in-house software updates on the old stuff.)
