Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I don't really know the dB rating, but it's not *that* bad. More on the Panaflo side than Tornado. :/
If you already have a running and quite silent PC and have the fan at your disposal, you can try and plug it on the Chassis fan mobo connector. Or maybe with an 3/4 pins adaptor and a PSU w/ tester. Hope that helped.
i think dba would be around mid-high 20s, cfm won't be too high.
i think stock ones are quite, but if u want something better n quite go for zalman 7k series.