If you're looking for a customizable shopping cart system with built-in affiliate management, PayKickstart offers an integration with MemberMouse. The following support article from their knowledge base details the steps to set up the integration:
https://support.paykickstart.com/knowledge-base/integrating-member-mouse/
You can find more information about PayKickstart features in this video:
Note: PayKickstart has developed an integration with MemberMouse, MemberMouse has not developed the integration with PayKickstart.
What this means for you as a customer, in practice, is that when a member signs up with you, PayKickstart creates a member account for them in MemberMouse. However, PayKickstart takes over the subscription management. In essence, you would only be using MemberMouse for access rights and scheduling of protected content. It also removes MemberMouse's affiliate integration features.
As with all 3rd Party Solution solutions, if you are having difficulty integrating or have questions about how it would work, please contact the 3rd Party service. They created the integration, so they alone understand how it is supposed to operate.