I'm surprised at your choice of motherboard. It's a mini-ATX format?
As for the position of the H70, it's fine. You'd probably do a bit better with the pump rotated 90 degrees anticlockwise, and the radiator rotated 90 degrees clockwise. That way, the tubing will not bend quite so much, and the barbs on the pump wont be interfering with each other.
Heres my current setup -
Intel i7 920 D0@4.2Ghz (200x21)
Gigabyte GA-X58A-UD3R
Corsair 6Gb DDR3-1600 (1866 modules)
nVidia GTX470 1.2Gb
2xWD3000HLFS RAID0
Creative SB X-Fi
Cooled by a single loop (CPU only) - EK Supreme HF, EK Coolstream 120x3. Currently only got one GTX470 in there, though I have another sitting aside. Pondering whether to grab waterblocks for both and put them in the loop or get a single newer card. Probably wait until the new year before deciding. http://img641.imageshack.us/img641/5938/cimg20620.jpg