Head hunter service for contract work?

Hi all,

I'm curious to know if anyone knows of services that act as headhunters for freelance/contract work. Basically I'd like someone to do outbound marketing for my one-man video production company to large companies in NYC. Ideally, like regular head hunters for salaried jobs they'd be free or charge a nominal fee up front and then take a percentage from the contract or a payment from the firms doing the recruiting. Any thoughts?