Upgrading questions, I really need some detailed advice!

I would say that is a okay choice, just you RAM will be slow compared to the rest of your system. Also, that fan doesn't mention LGA775, so I don't think you can use it. As for the case, the CM 912 should be good. Also, I wold recommend the Corsair A70 for the HSF.

Make sure the cooler is compatible with LGA 775.
Other thing are well and good

GTX 560 is good, it'll suit 1920x1080.

I'm using this case....

http://www.thermaltakeusa.com/Product.aspx?C=1390&ID=18...

Within it contains:

Q6600 o/c'd to 3.2ghz on air, or 3.6ghz with Corsair's H50.

The GTX 570 has about 3 inches to spare, even with the power connectors on the side toward the hdd cages.

It'll support any size air cooler as far as I can tell. It looks nice and the big fans really help with gpu cooling.

My main complaint is that the H50's radiator and fan setup interferes with the case lid's giant fan. Since the H50's a closed system, I cant route the tubes/radiator to the outside, so in that config, I have the case lid leaning up against the tower and not screwed in lol...

Anyway, it's really hard for you to go wrong if you've chosen air cooling and a single gpu setup.

I threw this up just so you realize my mistake in choosing a case for a very similar setup to yours. When you nail down all the parts you want to put in a case, you can always email the case support team to verify compatibility. This is what I did *after* I made my purchases, so just keep that in mind.

Thermaltake V9 Black Edition
Thermaltake TR2 RX-850 PSU
Asus P5N-D
Intel Q6600
Thermaltake V1 CPU Cooler O'Cs to 3.2ghz
Corsair H50 O'Cs to 3.6ghz (not in use atm)
G.skill DDR2 Memory - 8GB 1066mhz
PNY GTX 570
WD Raptors RAID 0
WD 1TB drives RAID 1