SuperBestAudioFriends is just a discussion forum as far as I know. Unfortunately, there is currently no way to sign up. I found an audiogon member that was also a member on that site that sent a message to their administrators, so hopefully they'll get it figured out.
SuperBestAudioFriends
If anyone is a member on this site, I tried to sign up, but the recaptcha that they require is not loading. This is the case for the contact us form as well, so there is no way to send them a message. If you are a member, can you please let them know.