I like to create an eCommerce Website with eBayintegration.
You can use nopCommerce[preferred] or Magento Commerce open sourcesoftware or suggest an alternative which is cost effective. All usefulextensions needs to be installed for these platforms. It should be a completewebsite with all the functions used in regular retail ecommerce website.
All eBay Store and Auction functions and orderprocessing will be managed from the website.
It should have Complete Shipping integrationwith USPS, FedEx and UPS for Real Time Pricing, Fixed Shipping Price, FreeShipping, Shipping Location Limitation, Store PickUps and should also allow toPrint Labels.
I will provide a basic layout design of theHome, Category and Product Details pages and you will need to customise thesepages according to that.
Integration of PayPal Website Payments Pro(Direct and Express).
I will tell the Form Fields for the Productsentry Form.
I would prefer to have one-step/two-stepcheckout.
Search Engine Optimization.
QuickBooks Integration if possible.
Google Analytics Integration.
Website will be hosted on shared hosting serverlike www.GoDaddy.com. 
Enter sample data and Perform all Systemand Unit testing of cart and admin functionality to validate accuracy ofinstallations for at least 25 orders which should remain in thedatabase for validation as an acceptance test performed later by me
Complete Email functionality testing for allalerts.
You will need to Testing and validation ofentire server environment for compatibility and correct operations for an entire Unit Test fortypical eCommerce functions in Cart and in the Admin area.
Verify and validate any other features andfunctions of the system to assure a perfectly bug-free implementation.