Since you guys are not powering the front wheels, you should probably swap them out for something with less traction.
The
Andymark 6" Omnis would work well.
Also, the rules aren't exactly clear, but it looks as though the DIN rails are required. Check the best practices and the electronics manual linked under section 8 of the manual on the usfirst site.
Also, those panels posted above with the white wires are 254's.