Cooling Yet another "Diving into Water" Thread...

Hi all,
I've decided that the fan on my Asus 8800GT is far too loud. Combine that with the fact that Asus have cocked about with the card's bios, so you can't change the fan speed, and it does grate a little.

I'm wanting to jump into watercooling instead.
For the CPU block and pump, I'm almost definite on an Apogee GT and a D5 Vario.
Reservoir will probably be a bayres that I can hide behind a bay blank in my Coolermaster CM690.
Tubing? Probaby 1/2" ID, as that's what's on the D5 I'm looking at, but I don't know if there are any options - Tygon's okay, right?
For the 8800GT, I think an EKFC88 8800GT block will do?
BUT, the biggest question is: What will be best, a 3x120mm Radiator, or a 2x120mm Radiator?

Will a 240 be able to dissipate heat efficiently enough?
Will a 360 have too much capacity?

I'm not sure what brand/model rad to go for either, I'm going second hand on a shoestring here, so may have to see what people have got in the FS forum!

TIA.

 

Tygon is the best but very expensive. 2x120 should cut it I think (second hand rads are OK I think).