Custom t-shirt shop

Hello. We are accetimg bids for a custom t-shirt design shop. There are quite a few out there, and we are oen to suggestions. Below are our requirements: 1) We want to allow our customers to be able to log onto the site and choose their shirt color, sizes and style. They should also be able to upload their design and add text. 2) We need to set a minimum quantity per designed t-shirt purchased. For example, we have set our minimum at 24. If the customer chooses 6 medium and 18 large, they hae met the minimum quantity requirements. 3) We want the ablilty to have different pricing per quantity. If the customer purchases 24 shirts, then they recieve one price. If they decide they want 144, then their price should reflect a quantity discount. they should be able to log in to the store to see their special pricing. 4) We want to have separate pricing per customer. Some of our larger clients recieve different pricing than the set standard price. We also want the option to allow discount coupons for customers to recieve a reduction from the standard pricing (example 5% off an order or free shipping). 5) We want the ability to show an "instant quote". When the customer creates their shirt, we would like the price to reflect their design as well as any quantity discount attained. 6) Ability for back-end administration. We adjust our pricing from time to time, as well as add new products. We need to be able to make changes as necessary. We prefer to work with a company in the US, however we are open to any reasonable bid from any locale. Some examples we are looking at are as follows: [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL]