I'll echo dipstick's suggestion, the slk-900A by thermalright for a socket A processor is about as good as it gets for air-cooling. I'm using an NF7-S rev2.0 in my current rig, the only difference is that I'm using a 70mm TMD fan instead of a 90mm fan.
drwho
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It's about time, it's about space.
XP Pro SP 1
Kingwin KT 436B-WM w/Vantec "Stealth" 520 W
NF7-S rev 2.0 B 18
XP 3200+ slk-900A w/TMD 70mm
Tmos Twister PC3700 (2x512)
Tyan Tachyon G9700 Pro
Maxtor 30 GB Dbak Plus (system)
Maxtor 60 GB Dbak Plus 9 (storage)
Liteon DVD 16x
Liteon 48x12x48 cd-rw