Those seem like well conceived upgrades for a $250 budget. I would be tempted to go for a 1,200 rpm S-Flex on the CPU to help keep the idle and load temps under control when you overclock to 3GHz. I don't see any CPU cooler. I'm assuming that you will be recycling the Big Typhoon. You're right, at $...

Be mindful of the fans installed on your case and your CPU heatsink. There's a nice review of 120mm fans right here on SPCR (http://www.silentpcreview.com/article695-page1.html).

Also, make sure you get a motherboard with passive cooling on the chipset.

The Antec NeoHE 550 I use in my Antec SOLO case is only audible when it spins up (upon hitting the power button) and if I overclock the system too hard. A tough overclocks turns my silent PS into a loud beast. The ducted approach linked by qviri seems like a great way to ensure that the PS has a hea...

I would be concerned about restrictive air flow within the case. The only paths for air to travel out of your case are through the PS and through the CPU heatsink and duct. Both flow paths are quite restrictive, which will reduce the volumetric flow rate of air through your case. Watch the motherboa...

System Specs Proc: Intel E6600 Cooler: Scythe Ninja with 120mm Nexus Real Silent Thermal grease: Zalman ZM-STG1 Mobo: Asus P5B Deluxe (passively cooled) Case: Antec SOLO Case fan: 120mm Nexus Real Silent (replaced Antec fan) PS: Antec NeoHE 550 HDD 1 (suspended): Samsung SP2504C (OS, pics, music) H...