Tony,
I look at mobile home parks with at least 80-100 spaces. With a park of this size it will allow you to support a good manager. With a good manager in place management from a far is not difficult. Technology will allow you to manage from afar with ease.
Hey John,
I use a program called gotomypc.com. It is $19.95/month (1 computer) or $34.95 (3 computers) and you can link into the onsite computer at your facility from anywhere in the world. I even one time linked into the onsite computer at one of my properties and the manager was playing Solitaire. I immediately called her on the phone and asked how the game was going and caught her red handed! 
Boy was she embarassed!
You can also install cameras (inside or outside) at your facility. If you have an internet connection the cost of monitoring of your facility will only be the initial purchase of the camera. Cameras are about $99 - $300. You can even get cameras that you can pan remotely from your computer.