I'm doing the same thing as you, Elcs, and I've only spend $176 shipped so far. But then again, I'm not using a HC or rad, but just a large bucket
$87.22 - Innovative's GF4 & NB blocks.
$15.75 - Maxi Jet 295GPH
$54.85 - TC-4
$18.18 - 10ft Tygon
All prices are shipped, and you can save ~$30 if you go with Becooling's NB&GF4 blocks, I just like the purdy Innovatives
The result won't be totally quiet, as I'll still have the PSU fan & pump, but pretty close. You probably don't want to get the Maxi jet, though, I just don't think it has enough power for 3 blocks. Ehiem really is the way to go for silence, or so I've read, so all in all you're probably looking at $200. Kinda like gmat said