The payment gateway must work with WHMCS and not with your reseller account (ResellerClub, NetEarthOne, Resell.biz, etc.). Provisioning will happen once a customer has paid the invoice through the payment gateway you offer with your WHMCS.
Wanted to know if I can manage, buying of domains, hosting, and other services via your modules.
Yes, it does not matter which payment gateway you use.
2018! A new challenge with a lot of changes coming up ...
We just released for all v3 and v4 Modules updates to be in compliance with the new upcoming WHMCS 7.5 system requirements for PHP 7.1. All modules have been reviewed and updated where necessary to work with PHP 7.1 and also to address some bugfixes.