I decided to use the Parkzone T-28 as the initial plane for my APM.  I picked it beacause it is a straight forward 4 channel foam plane that fits in my trunk assembled and it has a huge removable canopy.  I am going to move the tail servos to the fuselage just ahead of the tail, install a seperate nose wheel steering servo under the nose, and move the battery forward.  This will completely empty out the large area under the canopy for the electronics.  I also cut the bottom of the canopy flush to increase the space.

The pictures are of a quick mock up to check the center of gravity before I do anything permanant. It looks like it is in the ballpark.

Another good feature is that somewhere I saw a replacement canopy with a camera on it, it looks like it would be easy to make also.

I like flying this plane and learned a lot while flying it. I am building a completely new plane for the APM, the old one has been through a lot!  I am wondering if anybody else is using this or similar planes?