shopping cart integrate with authorize.net

I am currently have a business website with a shopping cart, and I need someone who can integrate the shopping cart to work with the credit card processing gateway authorize.net. The shopping cart also need a minor update. You must have experience working with 256 bit SSL Encryption to secure important data. Also, you must have experience working with the ecommerce website. Here are other requirements. 1) Must have experience working with credit card processing gateway. 2) Experience working with [login to view URL] 256 bit SSL encryption 3) Must be reliable and have good credential 3) Please bit with time frame to complete the project and describe your experience