Healthcare company in need of recommendation for Affiliate Management Service

I am looking for an Affiliate Program software/service recommendation to run a new program as a vendor. Something you have used before and can discuss.

The service we are selling is currently in operation and has been for 2+ years. We are not looking for an agency, just a service/network to roll this out and manage our affiliates.

I have been given the opportunity to develop an affiliate program for a B2C healthcare service offering and I am looking for a good platform to create and manage a program. I am the marketing contractor and the client would be providing services. This would be a JV project. The affiliate payout would be on start up, as well as have a monthly reoccurring revenue paid out based on the end client continuing their membership in the program.

I have done a number of searches here and elsewhere and know of at least 12 companies/programs that are possibilities. I need the service to accept payment for the start-up and manage reoccurring monthly memberships (or purchase an annual contract). The subscription information would be used to manually create the client in the service system, at least in the beginning. We would automate once we were happy with the workflow.

Can you recommend a provider that would be good to work with? I want to make sure that payouts are easy and instantaneous to seasoned affiliates. Thanks