Going back to original question... I have spent about 500 quid with some change for all custom three block loop.
Brace for wall of text...
Mind you i needed some tools, thermal material, then due to me planning for a wallmount build i missed one crucial detail and it cost me some more, mostly due to shipping cost for unplanned parts. The mistake i made was i planned out of the case and didnt take into account needed 90 degree fittings to get piping round power supply. Near had to halt all construction due to videocards being already disassembled for waterblock fitting and mis-measurement of the gap between videocards, where i needed to make a tube loop instead of planned bridge-like short tube. Lesson here - plan to the tiniest detail, every single fitting in the loop, you have to account for every component in the space you need to fit it in.
Also, i nearly lost my cool when i discovered that EK compression fittings nearly unusable on GTX480 Heatkiller x3 blocks, because 2 fittings only fit if i force knurling of both against each other with pliers (absolutely no damage to blocks, too close for about 0.25mm, but made it unscrewable by hand...) Lesson here: Dont assume your parts will fit even if they fit everywhere else...
Did nice case mod to flip over powersupply with intake fan under the case and cable management, cut holes in the bottom and cut up motherboard tray to allow cpu bracket mounting and replacement without taking out whole motherboard, and to hide cables under the tray. Only to be thwarted by the fact that my pump res doesnt really fit because of solid cage. I either have to cut it or move res pump. I planned my rads on the outside, but pump/res on the inside... Didnt happen, had to mount pump/res on the outside... because i almost entirely reassembled and couldnt be bothered to take all out again and cut a piece of the cage out... Lesson here - again, plan your space out, in its entirety.
I also failed to plan for external rad ventilation, which means running power cables to the outside. I soldered an adapter to run all 4 fans off one molex at 7v, but it looks ugly...
My system now looks like Dr. Frankenstein had a go at it. It works like a charm though. Not a single leak (that part was way nerve wracking though

). Temps are marvelous due to fat 280x60mm rads and good fans (4x 140mm Silverstone AP141).
I still consider it a stop-gap build before i start rebuilding it to my initially planned wallmount, its just that my wife doesnt like me much now because i caused a small black hole in family budget with my bs and i have to live with my rig the way it is now ...
So there...
P.S. Also, i hate my PSU now (OCZ ZX1000w) with its seriously anoying coil whine... Lesson here - GET A QUIET PSU !!!...