Design a ecommerce website using magneto as a CMS

I would like to know how you are going to approach this project. How will I go in to update the pictures and prices? Are you planning to create a HTML 5 website from scratch or use a WordPress template? These are the basic functions I need in my website 1. An E-commerce website " must be able to keep track of inventory" 2. I have to have full access to edit any portion of the website as freely and have access to change pictures, update inventory and pricing without the help from you. 3. I need it linked to a merchant account. Currently I am thinking of using PayPal which would keep track of the inventory as well, however in the future I need a system that customers can pay online and the money will go to the bank with the least amount paid for merchant services. I am willing to take suggestions on any ideas. Do you think I should stick with PayPal? 4. I am trying to create a business model which provides customers with the ability to become their own distributor. For this to happen they need to create a distributor account with the website. The first level will be a minimum purchase of 20-100 pcs which they will get a 40% discount from MSRP. The next level will be from 100-500 which would give them a 50% discount and so on till we reach a 70% discount which is the max for a distributor. These levels have to be programs into a section of the website as well. 5. For each product there should be a section to insert ingredient list and update the content and description of the product. 6. The website should be mobile phone compatible. 7. SEO is very important and it should be built into the website.