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.
Well, the 2500+ is probably your best bang for the buck. A 2600+ probably will overclock as high as a 2500+ will, but I doubt it would do more. The 2500+ is 1.83ghZ and the 2600+ is 1.9ghZ.
I'd probably go with the 2500+, or if you want an unlocked one, then a mobile 2500+ (or 2400+).