After wanting a little more performance from my new 965BE I decided to look into overclocking. I changed the settings through the bios not Windows. I am currently running at 4.0ghz via clock multiplier [no changes to FSB] and changed the voltage to 1.45v
AMD Pheonom II X4 965BE 125w rev C
Coolermaster Geminii S fan with Coolermaster Exacalibur 120mm fan [instead of stock]
Used DIAMOND IC7 for thermal paste
Biostar TA890 FXE ATX motherboard
Apevia Xplorer2 tower case with 120mm rear exhaust [Coolermaster that came with Geminii S] stock Apevia 200mm intake on side panel [no idea of cfm/rpm ratings] and stock Apevia intake at front of case.
61C is nothing to be worried about. prime95 is a good test. Personally if I am prime95 stable, I am satisfied. But if you are looking for more tests for your CPU, LinX is another good stress test.
What would your reasons be for replacing the fans? Are you looking for something quieter or do you just want lower temps. I don't think you would need to replace your fans, but there's nothing wrong with more cfm of air moved.