I use the sticky-back velcro.
You neverknow what you will do with that next year. The foam tape will be hard to remove.
Also, I'm hoping that you've seen the posts about removing the LEDs on the RX board... The little transformer on the SSR4 is pretty heavily loaded with the DMX PIC and the wireless receiver, and those two LEDs draw a lot of power...
I had trouble with the PIC rebooting last year and ended up pulling out the wireless module before the discussion on removing the LEDs. I had some pretty long power cords getting to where these were, which I'm sure didn't help...
RM