Responses
@MOI
This is for your request, sorry it took forever (hope you don't mind I combined everything even though you just asked for s&m).
beta
Another list called The BDSM List. It's no where near from finished since it will be containing every thing from just one of them like sadists, to all bondage/discipline/sadist/masochist, and everything in between. But in case you guys want to check it out already here it is:
http://www.mangago.zone/home/mangalist/21489/?filter=&page=1