E Commerce Backend Customization By bbgreg on Sep 7 Max Bid: Open to fair suggestions

We require a custom modification of the E-Commerce software Interspire Shopping Cart Version 5.5.4.  Specifically, we need a modification to the payment processing API for manual credit card transactions. 
At the moment, the software will only collect this information or process payments automatically at the time of order placement.  We require the ability to automatically send through a credit card payment (API) on demand from within the program, such that the fields are automatically populated with the correct information for processing.

Requirements Interview Answers:

To help you bid more accurately, the employer was interviewed about the requirements for this project. Below are their answers.