Does anyone know of any databases where you can search for independent contracting gigs or subcontracting opportunities with prime govt contracts?

I know of elance, but that's not really what I'm looking for. I've also looked at fbo.gov but that seems to target more well established firms. I'm looking to go solo and find a good contract to sub in to a larger govt agency.

I'm tired of business development and just want to do the work. CPA with over 10 years at same Big 4 firm doing financial analysis and some govt. consulting/audit remediation work. Would love to hear any suggestions of where to look for subcontracting or independent contracting opportunities.