Ya I put an H80 in an antec 900. I would not suggest trying to put that in a case no designed for it. Cases like the HAF 932 even have screw hole for the H100 in them talk about easy. If you like to mod have at it but I am betting it will end up a bit messy plus it is a closed loop so to pass the rad outside you will need a heck of a hole...
I don't see anyy reason a H50 can't have the pump as the high point, if you can fit the block through the Pcie slots it would save cutting the mesh out,
On a sidenote to Thently, those grommet holes are for real watercooling loops, you can't feed closed loop systems tubes through them without cutting, which is highly advised against