I like the 3d images
I've been mapping the FX5900 U dimensions myself but only in 2d for hole positions really.
The biggest problem I can see is the weight.... something I'm always fighting, but your design is a lot of copper on the card.
Also to make it easier to fit consider 3/8" barbs and do a NB block with 3/8" also then split the output from your CPU block to both (assuming it's 1/2"). The flow will be enough for both and should help keep the overall system flow rate good.
I'm pretty certain you've see my build....... if not it's
HERE.
One other thing to consider if you haven't is the bottom edge of the blocks where the cards gold fingers are. Make sure you double check that there are no mobo components in this area as it can be very tight with some. Below is the 9700 cooler showing how tight the ram block is to the ram slots.
