This block won't work.
The plexi/Polycarbonate Top will crush because of the pressure from the small screws. On some edges, there are 3-5cm between the screws, i don't think that you can get it proof there because polycarbonat is more flexible than you would imagine, especially when it is so thin because of the big channels.
The fin area ist much too complicated to produce it at a realistic level of costs. 0,5mm cutting tools are very rare and expensive. the smallest diameter what i would use ist 2mm.
The block will be much heavier as a zalman heatpipe (330g)and thats the maximum what is possible without risk that your card breaks.
The block wont fit on a 9700 series card, it is a little big in the corner.
The cooler all in all looks nice, but i have to tell you these difficulties, because i made these faults before too.
I know what i am talking about, i constructed a similar cooler and i had to fight the same problems. My cooler now has a less large diameter, less flow, less wheigt, less thickness (1slot!) but some more screws.
Here is the link to the original Thread (in German). Scroll down and view the next page, there are only a few pics, because it is still in the state of prototype, but it will be finished in a few days.
Sorry for my bad english, but i hope you'll understand what i meant
another pic: