I can’t take on any private work, but I can give you some help through this forum. Most of what you are looking to do is provided by the WP Discourse plugin out of the box. By default, the WP Discourse plugin will give all users on your WordPress site access to your Discourse forum. To limit access to users who have purchased a membership, we just need to know how to fill in this part of the code that I posted above:
/* Some condition that returns true if the user doesn't meet the membership requirement */
How to get the membership level for a user is documented here: https://docs.woocommerce.com/document/woocommerce-memberships-function-reference/#section-6. Anyone who has some experience with WordPress programming should be able to help with this. It won’t require any knowledge of Discourse to figure it out.