Best plugin for private section

Hello,
I would like to let people register on my website with nicely integrated forms (like Membership does).
The membership is to be free (for now anyway).
And the only thing users should be able to do, would be to create a post (multiple posts) in one of the custom post types I created (waiting for approval to be published).
What would you suggest for that ?

Thank you very much for the great plugins !
Alain