Copywriter for social platforms - long-term relationship

I have many social media clients that I need to compile content for. Most of it would be pulling information from their individual websites and constructing engaging posts for Facebook - I will then rework it for other platforms as well. I am willing to discuss costing. But at the moment I am looking at 20 posts for $15. Each post needs to be between 200 to 600 characters with a cool engaging twist or call to action. Either engagement on the social site or leading back to the website.

HOW IT WILL WORK:

I send the request for the amount of content posts and suggested themes - you then work on the topics through web research and company website. I review and once happy, all will be approved.

This is a long-term relationship that I am looking for. Deadline driven and very well written English.