DiscourseConnect can act as an identity provider as well, but there currently is no Drupal module that can act as a client.
This would be more a Drupal project than a Discourse project, so maybe it’s better to ask this in a Drupal forum.
Nevertheless, our PHP skills are pretty good. We estimate this project to be in the 1-2k USD range. If you’re interested in discussing this further, please send me a PM.