I wouldn't really suggest the HK block. It is expensive and not the top dog anymore (plus the copper is ugly IMO). Personally I think the newer Koolance blocks look and perform fabulously. However no one in Canada really stocks them.
As for fittings I am a huge fan of Bitspower barb fittings. With Primoflex LTR tubing they fit like a glove. With 3/8ID tubing and fittings I don't even use clamps. That is how well and tight they fit.
For the fittings between the video cards I use these
SLI VID Connector - G 1/4 - 1/2/3 Slot - Silver SLI VID Connector - G 1/4 - 1/2/3 Slot - Silver [1403] - $8.99 : DazMode, Canadian PC Water Cooling and Modding Store
Much cheaper than a link, and not so hugely bulky.
As for a pump I would go w/ the new Swiftech MCP35X. It can be controlled via a motherboard fan PWM fan header w/o any issues. That and it has an 'aftermarket' top built in.