As everyone else has said, this is not a good situation. You don't want the overhead and risk of providing software security let along physical security for the storage of personal information unless your business model depends on shaving the fractions of a percent that it may save you in processing.

In all seriousness, get set up with a major processor and get on with your business. (PayFlowPro would work well for the recurring payments you seem to need as a feature.)

I was the CEO for a company that one Phase I and Phase II SBIR grants joint with a University, and it can be a very good thing if the goals of the grant and your product goals are closely aligned. The goal of the grant is to fund the product development, not to make you rich, and you'll make a very small (like <10%) margin on the work.