Simple registration form and database

I need a simple registration system for my site. The registration flow is quite simple: 1. The customer chooses a service from a dropdown list on the landing page and pushes continue 2. Either on the next page or in a pop-up he/she is asked to enter 3 fields of information (name, email, phone nr) 3. Finally he/she is taken to the payment page (Paypal) where the customer is asked to subscribe to the recurring billing service. The page is built on a wordpress template and all thats missing is a registration system that would blend together with the design of the rest of the site. The database needed is really basic (can be MS Access) and should only contain the the information mentioned above pluss the option to see if the subscribed customer has an active membership, which means some integration with the payment providers API. Since this should be quite an easy task, I expect the job to be done quickly. Please show some previous experience with similar tasks. Thank You, Andrew