Auction site

we want to create an auction site (similar to tons that exist for lowest unique bid or like ebay). You can use every CMS that exists (we don't care), but it has to integrate a powerful commercial tool for invoice report and so on. If you want to use a NON-free CMS i'll pay for the license. You can use every auction based tool that exists (we don't care ...i don't know like "i-lance"), in case it's a NON-free tool we'll pay for the license. Prerequisites: 1) we'll commit the project only after we'll see a demo 2) we need a name, address and registration num# of the company or the developer and a landline phone, msn contact and skype contact 3) we need the source code (every part of it) 4) we'll pay 5% of the amount requested after 1 week, when you show us a personalized demo 5) After another week, if you don't show us improvement we'll drop the project, if you really are working there we'll pay another 15% 6) we'll pay the total amount when you'll give us the complete project and installed it on our server Note: for the last total payment we need a valid ID, NDA, copyright and letter signed for responsibility about not leaving backdoor open or giving away the source code.