okc is the best. Its 100% regional for how useful it is. i live in a strong poly area, so matches are easy to find. Other regions might not be as good.
There is a polyscentric dating site. I disliked it. Anyone who I would have been curious about wasn't "active" anyone who was no where near my type was. Can't remember the site of course...I found it beyond useless.
have you tried local poly meetups etc? Munches etc. Online might not be the answer in this situation.