Hey guys, I made a post a few months back and recieved heaps of helpful advice. Life got busy for a while but I've put this build off for too long now so I'm hoping to pull the trigger in the next 48 hours. Heres my final proposed system, now a fully fledged budget gaming system which I'm confident will also fill my requirements for a silent daw system as well.

CASE: Antec Solo (with Nexus RS120mm as exhaust)
CPU: i5 760
HS: Scythe Mugen 2 (PWM fan included)
MB: ASUS P7P55D-E LX
PSU: Seasonic X-400 Fanless Gold 400W
RAM: Kingston ValueRAM 4gb (2x2gb)
GPU: Gigabyte 5770 Silent Cell

HDD 1: Samsung SpinPoint F3 1TB HD103SJ
HDD 2: Samsung SpinPoint F3 500GB HD502HJ

So at this point I'm confident the system will be quiet, however I am concerned about heat. My plan at the moment is just to run two fans, (HS and exhaust) however I understand there are other options such as adding two intake fans, and I've read about people putting a fan on their passive GPU.

So I'd like some advice on whether I need to do more for the cooling, but if you have any other comments they would be appreciated as well!

The Silent Cell models can safely operate with GPU temperatures reaching 100 C. Solid caps and all that. There's no need to put a fan on it. You can open a slot cover below the graphics card to provide more fresh air, but AFAIR the Solo has half-open covers there, so it should be fine without any changes.

Adding intake fans will help a bit, but it will also make the thing noisier. If temperatures get really high, I'd rather recommend using an exhaust fan with a larger speed range (like a 1200 rpm S-FLEX) with some fan control mechanism (hardware or software, your choice) to make it faster under heavy load.

With 2 drives in the front you can safely add a front 92 mm fan and run it at constant 600-700 rpm. You won't heat the difference. You could align your HDDs to form sort of a duct to direct air to the VGA. Sure, the card will handle the heat fine, but there's no harm in giving it some air. A faster spinning 120 mm fan in the back will not help cool the card at all. It will help cool the PSU tho.

The HS fan and exhaust fan in push-pull should keep the cpu nice and cool. I'm a fan (no pun intended) of building a base system and then running stress tests to see how heat builds up. Then, add silent/low rpm fans to reduce temps in specific areas as needed rather than cranking up the rpm of the exhaust fan past the point of silence.

My HDD was running hotter than I liked, so I added a 92mm Scythe in the front at ~500rpm (silent).

The Gigabyte has gotten rave reviews. However, the 80W it generates has to go somewhere. Worst case, you'd need to add a low rpm fan. I'd build the system and see what the temps are first. Then go from there.