Ecommerce project

We are looking to add ecommerce capabilities on a web site that we have developed. We need customers to be able to pay pre-determined amounts of money by entering the credit card details online. We are not selling products so a shopping cart will not be applicable, but we will have a few options available for the customers to choose from (with the associate price for each option).

We need an expert on ecommerce to advise on which bank, bureau etc to use and also how we could implement this. We need someone that has done this many times before and can have it up and running as soon as possible.