Build a website similar to Spreadshirt.com

Hello We are looking to set-up a [login to view URL] like start-up. We want to allow designers to open up a shop for free, upload designs and sell them. We will print and ship the T-Shirts. The buyer pays to us and we'll pay a commission to the shop-owner at the end of the month. Here's what I have been looking for (explained as lucidly as possible) - 1. Front end ([login to view URL]) 2. New store owner registration + sub-domain for user ([login to view URL]) 3. Store customisation ability for store owner(store owner can add banner, change colors etc.) 4. Store Owner file upload (adobe illustrator design files we can check out and approve for printing) 5 Store owner can display a number of product images on his store (items for sale) and the sale can be made straight from the store-owner's subdomain. 6. Buyer login etc. 7. Database that maintains buyer information etc. 8. Some sort of system where the store owners do not have to re-register as buyers when they are shopping for products at other stores and similarly - the buyer doesn't have to re-register as seller when he wishes to open a store of his own. 9. Back-end support - tracking orders/ administrative view for the admin to see what store-owner has been doing what kind of business, what commissions need to be paid out to whom etc. 10. Any other critical idea that I missed. Right now we are looking for operating in India only, using Cash on Delivery (COD) for receiving payments and implementing the payment gateway called: CCAvenue. We will be giving out commissions to store owners via check and need everything to be on order with complete back-end for the admin. Here are some references for you: [login to view URL] (main site) [login to view URL] (store owner's site customised by store owner)