Add To Cart Bot for Art Prints - open to bidding -- 3

Hi, I am looking to create a bot that will automatically add art prints into concurrent shopping carts (and to pay via paypal). It is critical this bot is extremely fast. Also it must work on my MacBook Pro. Furthermore it must be easy to handle as I am not not really good when it comes to IT stuff (--> quick and simple manual is required). Basically these stores release different art prints at a set time (e.g. 3 a.m.). Im looking to... on my Macbook Pro 1. add art prints to concurrent carts (6+ max) as soon as they are available on the page (important: It might be that there is more than one art print released at a time. In this case, each print has to be handled separately, i.e. added to concurrent carts, as there are rules that only 1 print can be purchased at a time) 2. it must work for at least three different art print providers (particular pages will be communicated separately). Finally, the bot must be usable on several Macs. Thanks