Customization of e-commerce WordPress Multisite

I wish get custom developed my existing wp-multisite [login to view URL] The obectives are...The site should be like [login to view URL] and [login to view URL] where one can become member, upload work, upload personal details, sell stuff, pay commission, discuss in forum, write in blogs etc etc. The site design will be same as it is. It will be better if I get to see any similar projects you had done earlier. I would be happy to provide more details if asked. I expect people to quote me a price first.