I think your biggest challenge is not in finding employers, but getting the community of developers registered on it. I would probably position it less as a job hunting site and more as a 'show off your projects' type site. Once you get enough developers on the site then adding a job board section becomes a no brainer.

Have you thought about integrating StackOverflow as well? E.g. not just the code they've written, but the programming advice they've given.