Not sure there is a STW surfing equivalent – surfers tend to spend more of their time doing their chosen sport rather than buying stuff / arguing about it. None of the big forums are all that active particularly if there is a decent swell!
MagicSeaweed is probably your best bet for general advice etc
http://community.magicseaweed.com/
I can remember when A1surf and Surfmagic used to be the main ones but the first is full of spam these days and the second one met it’s demise about 10 years ago.
There are some regional / local forums if you scout around though.