starting to buy all my watercooling bits now, got my gpu block on the way from kemp and im just looking around for what other bits i want. I will be getting a Laing DDC. my first problem arrises here, ddc is 3/8ths and the gpu block is 1/4". i know this is no big problem on its own but i now cant decide what cpu block, rad and tubing size i should be going for? would a 3/8ths tube system and all 1/4" componants be ok? and if so, whats the minumum rad requirement be? would a 3cm thick dual 120 do pretty heavily OCd 7800gtx and X2-3800 ? if not do i go thicker or longer?