I pretty much hit the jackpot.
My wife agreed to try a couple swap with me.

I have no idea where to even begin to try and find a willing / attractive couple.

Does anyone have any idea of a site like TER specifically for swinging ?

somewhat regional. Tell me the state in which you live, and I can recommend a site!

As a veteran swinger who offers sexy swing club dates here in S FL,  I'm always happy to help!

Tabu

Have you already been swinging? If your wife is hot, have her create a free profile on AFF and then set her search to couples only and watch the swarm... If not, you can always join swing groups in your area and just wait until you find the right couple that you click with and find the right guy you would allow to screw your wife...