Sneaker Online Release Program

Question description
I need someone to make me a program. It will need to run on MAC. Must be easy to use and user friendly. When footlocker, footaction, and eastbay release shoes online, they provide a “countdown link” on a product page. You may select your size and then once the timer runs out, you have to click add to cart. I need to be able to tell the program what size I want to get and which product I want to get. The program needs to automatically add the size to the cart. The program interface must have rows as follows.
Store Name (Footlocker, eastbay, footaction) / Username / Password / Product (the one you want to buy) / Size (of the product) / link to the my cart page of that account
I need to be able to tell it to add a size of a product to my account. Must be able to add as many accounts as possible.
MUST WORK ON MAC
Add to cart for all of the accounts must run in background!