296766 shopping cart

I currently sell three versions of an info product online--two of the versions offer a downloadable product. I need a new shopping card set up that will be compatable with my credit card processor "2CheckOut" (and they have a basic built in system already). The shoping cart should have the folowing choices: 1) Quantity, 2) 5-6 shipping options (preferably a drop down menus), 3) Ability to charge state tax, 4) Deliver the successful purchaser of the two downlaodable versions to a Thank you and Download instruction page (I'll provide the text content), 5) a password/ UN access to the document (with some form of security, eg. rotating?) Finally, I will neeed this installed/set up to work with my current order page and 2checkout's system. In summary this is really just a basic shopping cart system for three products -- and 2 checkout already provides the basic system. If you know how to set up a shopping cart and if you are familiar with 2checkout, this job should really be quite simple.