Reccomended Cooling for 6400+

Currently have a cooler that is not very good with this cpu at stock. 68-70 idol (i know) well its causing problems (of course)

ill be using this: www.overclockers.co.uk for a cooler but am not sure on what to go for, money is no problem at the moment so best cooler is fine. its just knowing what one is the best for this cpu. any help would be cool thanks

When I bought my heatsink a while ago the Thermalright Ultra 120 and Thermalright Ultra 120 Extreme were at the top of the heatsink food chain. The Tuniq Tower 120 was up there as well.

I bought the Thermalright Ultra 120 (http://www.frozencpu.com/products/5387/cpu-tri-33/Thermalright_Ultra-120A_Universal_CPU_Heatsink_Socket_AM2_775_.html) with a Scythe Slipstream 1900 RPM (http://www.frozencpu.com/products/6488/fan-383/Scythe_Slip_Stream_120mm_x_25mm_Fan_-_1900_RPM_SY1225SL12SH.html) fan (I only run it at around 750 RPM's) and it keeps my Pentium D 820 (which is overclocked by 800MHz) at a steady 105F-110F (40.5C-43.3C).

im thinking maby this would be ok? http://www.overclockers.co.uk/showproduct.php?prodid=HS-045-AK&groupid=701&catid=57&subcat=821

I have an AMD 6400+ running at 3.3ghz (OC 3%) on an Asus M2N-SLI. I have been using the AI overclock in the Phoenix Award BIOS. When I go to 5% in Windows 7 I blue screen, in Vista it would drop my clock speed to 1ghz, become unstable, then blue screen. Both are x64 OS.

I'm wondering if the board just can't handle more than 3.3ghz? Or is the Asus AI overclock just crap?

AMD 6400+ 3.3ghz
Asus M2N-SLI
GeiL Black Dragon PC5300 8gb
Nvidia GeForce 8600 GT 1gb