Ejiro,
Glad to know you and glad to know Paystack is willing to develop a plugin to handle payments in moodle.
I am currently working on a moodle project for a client and the client wants to use paystack for payments. Integration with moodle has been hectic.
As of now, I had to setup a wordpress site with woocommerce to utilize the woocommerce paystack payment plugin, then enable Moodle Webservices API to try to communicate with the WP site. I am still in the process and hence cannot report whether or not it will work as expected.
However, I intend to look at some existing plugins and see if any new ideas will pop up.
Please kindly keep me posted if and when paystack comes through with the plugin.
Thanks