yeah, sorry about that! for some reason i was thinking you were making CPU blocks. DOH!
and for the designs of the GPU blocks.. iwouldnt even worry about making them fancy. i would just make them simple open areas without the internal designs(the two lines you have on both sides of the inlet thats in the middle) after all its just for a graphics card and its not really going to make a real huge difference anyway. like you said, its not as if there going to get as hot as your processor would, so it doesnt have to be as efficient.
why not do them yourself instead of geting a shop to do it? man, there is no better feeling than putting a block in your PC that you made yourself and have it perform on par or better than whats on the market to buy! weith the exception of a nice cold beer and a hot peice !!
in that order