312065 Ecommerce / Wholesale mod

Hi, We need a shopping cart system to take orders from our wholesale customers. It can be a mod from a open source software (Prestashop, ZenCart, Magento...) or it can also be a mod of a paid software (CS-Cart, X-Cart...). You can write also the script from scratch, but I guess it would be easier to mod something that already exists... The main idea is to allow our wholesale customers to place orders online and pay online. Our wholesale pricelist includes a lot of pricing levels (different for each products, but the same for all the customers), so this is where it becomes interesting... So the main features would be: 1- For each product, to allow multiple pricing levels (brackets). For example: Product A would be $10 from 1-10 cartons, $8 for 11-20 cartons and $6 for 21-40 cartons. More importantly, each product will have different attributes/variations (for example, a t-shirt would have different sizes and colors). The pricing levels will have to apply to the total of items ordered by products, and not by variation. For example: A customer orders: 5- Product A Green 5- Product A Black 5- Product A Red In this case the customer will receive the pricing for Product A in the 11-20 pricing bracket, because he ordered 15 items of the same product. The pricing levels will also have to be shown on the front end, so it can be clear on the product page what are the quantity discounts available to the customer. 2- Password protected shop. Only the wholesale customers with a proper account and password can access the B2B ordering site. 3- Account registering. The wholesale customers will have or can create an account, so they don't have to enter their shipping/billing info for each and every order. 4- Regular e-commerce software features (easy to use backend, catalogue creation, CMS, easy ordering process, credit card/Paypal processing...). 5- Clean and good looking skin. It can be the default skin of softwares like Prestashop or CS-Cart, but nothing old school and ugly like the default skin of OSCommerce... We are open for suggestions for this project. Let us know how you would like to do it in the PMB. We need someone who can begin to work on it quickly and deliver the final product fast. Serious bidders only. Thanks!