Wordpress Role Plugin

Hello, I am looking for a programmer to develop a plugin for Wordpress. I am creating a database by having users create posts, from which I can organize my data. This project calls for 5000+ users. However, I want to limit each user to only be able to create ONE post, after which they may not create anymore posts, and can only edit the single post they created. The current roles in wordpress do not allow this functionality and existing plugins only make it so that an admin must create the post and select which users can edit it. My preferred deadline is 2-4 weeks. The earlier you can get me a working plugin within the time frame the more I'll pay you. However, I will rank cost above deadline when taking bids into consideration. Again, I do not want the admin to have to create posts. The admin creates user profiles, and each user profile under the plugin role is limited to creating ONE post and editing that single post. Thank you, Steven Grives