Admin's note: This thread has been moved this post the JFBConnect Pre-Sales area.
While we haven't tested it specifically, there shouldn't be any problems with that configuration. We integrate very seamlessly with Kunena and allow for your user's FB Profiles to be automatically imported into their Kunena Profile. Additionally, we create stand Joomla user's and do not modify the core of Joomla in anyway. For this reason, I can't see any reason that additional user extensions would have conflicts, and in the past with other extensions, this hasn't been an issue.
If you run into anything, don't hesitate to contact us.