IS the Lian Li PC-73 going to be large enough? Google only turns up a few low resolution shots of the inside, but it looks like it'd be increadibly cramped if you tried to route 1/2 tube from 3 waterblocks.
EDIT: Nevermind found a better shot of the inside:
http://www.pc-cooling.de/catalog/tpl...092000d_gr.jpg
Looks like that case has a lot of potiential. YOu could fit a core up front and perhaps in the top rear, as well as a pump in several spots.