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.
For a single GPU, I recommend a PSU in the 500W range. 650W is overkill. A budget option would be the Antec NEO ECO 520W. A slightly higher-end and modular option is the Seasonic M12II 520W. If you want something on the high end of things, look at the Seasonic X-560, Kingwin Lazer Gold 550W, NZXT HALE90 550W, or the Enermax Modu87+ 500W.