Credit Card form with API

Hello,
I have an API from first data and I want to add a credit card form to my website. I do not want a shopping cart because I do not sell anything on my website because I provide marketing services not products, this is just for my clients to be able to go to a specific page and enter their credit card and invoice info (which has already been provided to them, I do not want a plugin that creates an invoice) and have it work with my frist data api. None of the credit card info is stored on my server, it is all done through first data. I will of course have a SSL. I know there are a lot of plugins available for shopping carts, but all I want is a credit card form. Can anyone suggest a good plugin to create this customized form with an easy place to input the api?

Thank you so much!