Congratulations on getting your own business going! By the way, do you post at AAPC also? There is someone with the same user name as you there, giving out awesome, thorough responses. If it is you, you clearly know your stuff, and I am sure that will help tremendously with getting clients for your new business.
As far as virtual office space goes, I would shelf that idea for now, and concentrate on setting up your home office suite. Once you know it is time to expand, revisit the idea. I have a feeling you will want "real" office space, when that time comes.