bidding website similar to freelancer or scriptlance

I have a business website already, I need to add bidding on projects similar to how freelancer or the old scriptlance use to work. Basically customers will be able to post projects they need done, and freelancers will be able to post questions and bid on the projects. Along with a bidding system like freelancer it should also include: 1) customers can post the project along with pictures and video if necessary and the site needs to limit the number of pictures and compress them on client side similar to how facebook works 2) freelancers can post questions and comments about the project and their bid amount, and the questions and bid amounts should be visible on the project page to everyone, not just the customer 3) a flagging system should be added, so if a customer posts an inappropriate project or a freelancer makes an inappropriate comment it can be flagged and a email will be sent to admin with a link to the project for review 4) some sort of administration page so projects can be removed, updated by admin, etc 5) messaging system between customers and freelancers 6) customers can update a project to add additional information, pictures or videos at a later time 7) customers can escrow an amount on the site 8) a dispute resolution process, where customers would post the issue, freelancer can respond and work out the situation or decide if it needs to be escalated to arbitration, possibly for a fee 9) profile pages for customers and freelancers, similar to ebay profile pages, where it displays a customized page for the user along with feedback