Custome digital product download E-commerce WordPress template

I'm testing waters to see how much it would cost to build a word press landing page template like the one attached below where users can; filter through products (title or category), add to cart, remove from cart, view cart total and proceed to check out without jumping through a bunch of pages. This would be the landing page, the next page would be the billing (name/email address) and PayPal guest/login check out. After checkout is complete I'd like the purchased products to be emailed to the customer. Open to discussion. Thanks