I'm not sure which system should I choose to support my 400/5.6 on 488 bogen ballhead? In my opinion RC4 or RC0 seem to be better option than RC2. 400/5.6 is not very heavy gear (will be sticked with 20D) but I want to be sure it has really good support system. What about differences between RC4 and RC0 -- again RC0 feels like more compact system, but kinda strange hexagonal looking... Is it practical?

One more thing - should I buy one more additional plate specially for camera, so when I take 400/5.6 off I could easily and quickly put 20D with shorter lens on?

Thanks for suggestions.