Marc,
No problem with mounting the ECU and pump close together. The fuel pump motor has filter capacitors on the brushes, and should be electrically clean. The fuel solenoid valves aren't a problem either. Batteries are a clean source of power. All of the equipment you have mentioned can be mounted together, in any location of your choice.

The only suggestion I would make would be to mount the I/O board (you called it a "jet ecu link circuit board") in a location that will allow you to watch the LED's during the start up procedure, if you have a JetCat engine.

Route the receiver antenna away from all electrical wires and you should be home free.
You will love the way the BVM MiG flys!

Harley Condra
BVM REP
JetCat REP