head unit recommendations

[JudgeM]

Hi All,

As part of my audio upgrade I am looking for a new headunit. My current JVC unit (pic 1) is doing its job, but I'd like a bit more.

Requirements:
-GPS navigation
-Bluetooth
-reverse camera input
-aux video input
-front 3.5mm aux in
-front USB in
-well known brand (sony, kenwood, pioneer, jvc, clarion, alpine, philips, etc)

So far the units here in NZ that can achieve this are close to NZ$1000. My budget is less than half of that.

I've been looking at these android/winCE units, in particular ones like ADAYO that claim to be oem units for Toyota. Does anyone have any experience with these not well known brand in terms of quality and performance ? I hear that the audio is not great and they are very slow.

I checked amazon and there are few good units but they dont come with NZ maps and it seems impossible to change the maps on them. Does anyone have a recommended well known brand (sony, pioneer etc) available in the US that can easily accept other maps ?

Another option I would consider is buying a unit that has everything I need except GPS navigation, then I can buy those navigation box that can easily take any maps. Has anyone tried these navigation boxes?

Finally, how about buying a factory toyota unit from somewhere ? could I change the maps on these or is it region specific ? Anyone know where to get factory toyota units ?