Is Vanilla the best choice for Single Sign On with Wordpress?

I'm working on a project, where people will have to sign in with a self-hosted Wordpress account, that process will direct them to a particular part of the site that's been setup. From there, they'll jump into the forum.
I've got the forum side of things setup, with different user roles, to keep different "groups" together. But, I'm still working through the Wordpress side of things.
In searching, there seems to be a lot of unanswered questions about using Single Sign On with Wordpress and Vanilla.
Is it worth pursuing? Or would a different forum be the better choice in the long run? I'm trying to set things up so they are scalable, so I need a solution that in the future can handle a hundred people.
Thanks for the feedback, it's very much appreciated.
Comments
Well, I assigned one professional web developer who has successfully integrated both wp and vanilla without any issues! I requested from him to replace wp login and users profile with vanilla's including some other tasks.
Vanilla is too easy to understand and optimize as he said. I agree with him and could see it the best platform to use and spend some bugs for custom work