i have a grandia gd08 and i just recently put an h80i into it. i was thinking about the h100i but just impulsively bought the h80i..
i wasnt sure how i was going to do it but i ended up screwing it into the case on the outside of the rear side 120mm fan mounts.
the h100 wouldnt work because theres only spacing for exactly 2 120mm fans. the h100 and h80 both have tubes coming out further than 120 mm which make it 140 or something. anyway i just cut some holes in the fan shroud and slid the heatsink through and mounted the rad on the outside like i said.
im opening my system up tomorrow and am going to take some pictures for another thread. if you want me to post them here, let me know. it is kinda tough to describe this stuff without pictures.