Moving to a house with a multitude of nice cool rooms and a nice cool basement that is beckoning a massive rad setup (2x 480 or 3x 360, or a big auto rad maybe? suggestions are welcome) with tubing routed through the wall or floor.

I know a single MCP-655/D5 (variable speed, always run it at 100%) is powerful, but how long of tubing run would you think would be OK for 1 pump for 2 rads + CPU block and eventually 2x GPU blocks (full cover variety, next gen ATI cards probably)

The pump will be housed in the rad box with a PSU and fans more than likely. If it is routed through the floor, the rad box will be connected to the ceiling braces so could be a relatively short run, but uphill. Maybe can go through a wall, but it would be a longer run, though level.

Is a single D5 good enough for those blocks and 2-3 feet of uphill run? Or 4-5 feet of lateral pumping? Again, pump will be at the same level as the radiators, blocks will either be level (4-5 feet away) or above (2-3 feet above)?