Starting An Agency

I'm exploring the possibility of starting an agency. I've worked agency for several years in an urban area with many hospitals (and agencies). I have a pretty good feel for what hospitals are paying agencies for nurses. I am thinking about a small recruitment of 12-20 experienced RNs, most of whom I have worked with and know to be excellent caregivers. And they are motivated to work. I know that I can charge less than any agency in the area, and at the same time pay my nurses more than anyone else, and still make money. My overhead will be very low, as I will run this from an office at home. I'm prepared for long hours and legwork. Certainly there are obstacles, not the least of which relates to payroll. I do not have the cash reserves to buffer against hospital billing cycles which can be anywhere from 2-4 weeks or more. Obviously, I want my nurses getting paid on time.
Any folks out there running an agency, or experienced in these matters? I'd appreciate any feedback.