Thanks for the positive comments and feedback all
pHaestus
I'm working towards making full card coolers in a limited, (small scale), production in the future, but my current methods are far to labour intensive & time consuming. Each cooler I make teaches me more about various important aspects, so it is very useful to me anyway. I pretty much think soldering is out, so a channel with o-ring is the next best thing. This would mean with a two part block (lid & base), could have cnc channel milling in the base part, with the cutting out done to datum points by water-jet cutting.
Blackeagle
The GPU finned part is not really how I intended it to be but I snapped the second of my two 2mm milling bits and didn't have any more, so decided to just finish it like that as I wanted to get on with it. The plan was to mill similar slots at 90 degrees to the others turning the slots into diamond shaped pins. I really don't think it will make a difference as long as there is flow of cool coolant, and it will favour the least resistant path which is through the more central slots anyway, not the right angled edges. 5900 U has GPU temp reporting in the drivers so I'll be able to see how well the GPU is cooled when it is finished.
Skeptic
The card having plenty of holes around stuff helps and I'm sure some commercial GF4 block will fit while still allowing use of the standard ram sinks. I can't confirm this but I heard Danger Den use the four holes close around the GPU for their water-block, but these are different spacing on 5900 U. Danger Den know about this and are making a new block or mounting system. This might be worth checking out because if it used the four holes it might not foul the ram sink.
Neo2Neo
Yeah I'm trying to get the projects written up for my site, but limited spare time usually gets used up making coolers, as that's what I prefer doing
The 9700 Pro build was detailed on Deviant PC and they have ceased now. The 9800 Pro I've not yet written up but there is some about it on Pro Forums
HERE