Or you do as I am doing and literally build an addition to the bottom of the case...
You do that and the planets align and the galaxies spread open before you with endless room and no interference from anything.
Ok a little dramatic, but in my case (literally) I am using a Micro case with two WC circuits.
I will have the rads and stuff on the lower plate with holes cut in the bottom of the actual case for pulling air out of upper portion through rads, then blown out the lower. Then some more holes for the vertical reservoir's and hose protrusion's.
Quickie side view...
Green = Rad
Orange = Shroud
Dark Blue = Pump(s)
Light Blue = Reservoir(s)
Violet = Fans
The design is to have them side by side, mirrored layout. I plan on having the rads just about sealed in own compartment, with mesh for the in/output, then the pumps and res'. solid walls.