I bought a Freezer Pro 7 and a Zalman 120mm fan (front mounted) for my E6400 over the weekend, installed it that day.
While my PC is about twice as noisy now (That front fan seems to be to blame, I think), my CPU is about ten to eighteen degrees cooler.
Idle with Intel HSF: 41 Celsius.
100% Dual Load, after about 5 minutes, with Intel HSF: about 56-58 Celsius
Idle with FP7/Front: 31 Celsius.
100% Dual Load: Between 40 and 44 Celsius.
I haven't attempted overclocking with the FP7 yet (I previously went up to 2.4 GHZ, and saw temps close to 67 Celsius), but it seems like it would do ok, at the very least.
The best part is that it's pretty cheap (25 Canadian where I got it) at times. Newegg seems really expensive.