Im thinking that the run would include 1 single fan radiator, and a 2 fan radiator, with it lookin something like this (PLEASE correct me if im wrong on the run):
The pump is at the bottom, and it pumps up to a single, 5 1/2 bay resevoir. Then it goes to the cpu, (then north-bridge, south-bridge?). From the CPU goes to a single radiator on the back 120mm fan slot. Then to a R600 chip with a FULL cooler (covers GPU, mem). Which then goes to the dual slot radiator at the bottom of the case. Then the pipe, b4 going to the pump, is intersected by a t line, (for the fill-port), finally to the pump.
(I plan to use all Danger Den parts)

Now that you can visualize it, would having a radiator horizontal effect anything? (the output would go strait to the intake of the pump)

Now, the questions:

1st off, lets say I put a radiator at the BOTTOM of my case, horizontaly. Air being drawn from the front fan port in the front of my case (made possible by a plexiglass tunnel making an airtight windtunnel) with hot air being expelled out through hole(s) in the bottom of my case.

2nd off, is that fluid XP+ stuff any good, and how many ounces would be needed? (also, would this need to be changed out every 6 months like the others?)

Lastly, does the northbridge/southbridge need to be watercooled for overclocking?

I plan to get a case with the PSU at the bottom to make this work.
If the horizontal radiator idea is a no, then just see if ive got the flow right.

If the horiz. is a go, then am I correct?

I know its long, but im just wonderin. Any takers?