If you could braid the motor to esc wires, that would help. I did that with my BL 18, and it helped quite a bit. Other then that spot you have it right now, i don't really see a better spot. Obviously you want it as far from the motor wires as possible, but I'd give that setup a shot. If that doesn't work, try that other radio, if that doesn't work, I'd look into cheap deals on the Traxxas 2.4ghz system. As you probably know, Fuse got one for $20.

I'd leave it where it is and test.