Вот, нашел насчет whmcs
WHMCS is an all-in-one client management, billing & support solution for online businesses. Handling everything from signup to termination, WHMCS is a powerful automation & support tool.
It is not limited to just web hosting, any business with a need for online billing, particularly of a recurring nature, for example services or memberships, then WHMCS can be a perfect solution.
Есть webmoney, yandex деньги итп, попробую для начала ее.