Found this thread after coming over from oc-forums and found people talking about blocks very similar in design
I already designed (on paper) a straight-thru block similar to the ones mentioned on the first page - Designed with maximum surface area and maximum water flow (no hard 90*, etc..). Currently designed with two rows of straight-thru holes, roughly 1/8" or so. It will be on a pelt so I assume I'll have a bit wider heat distribution than if it was sitting right on CPU core, so I'm designing the input & outputs for even flow without any stagnant channels.
With a lot if straight pathways cross drilled through the block, I know that laminar flow might pose a problem. I already have a few ideas on how to turbulate the flow inside each of the channels.
Using a Danner 500Gph magdrive pump with low flow restriction designed into every bit of the system- cooling CPU, GPU, & chipset (for now).