I have a couple of points/observations/etc.:
1. Speaking of that large window on the Axis/Vegas units (or any large window on any class A): Just cover it from the outside (A
Sunguard or
Magneshade cover). They keep a lot of the heat out, and look pretty good. (I have a Sunguard--you can immediately feel the difference inside when I put it on.) Granted they don't work while driving but while camping they are great (as a bonus people can't see into the fishbowl in the daytime).
2. The temperature sensor: Why not just run the A/C for a while and then use one of those laser thermometer's to find the warmest spot on the coils then just put the sensor there.