Hmmm, Having been in emergency services for the past 14 years, and radios for the past 15 years, let me give you my thoughts.
First and foremost, I would CERTAINLY make sure something like this is coordinated with local law enforcement and medical services. Calling it "personal emergency services" (or anything with the word EMERGENCY) will run afoul of many entities. Then you get into state issues of certification (emergency vehicle, taxi, tow truck, etc.). And should something go wrong (like little old lady calls you to come hook up her oxygen but it somehow gets messed up and she dies) where it is determined that you or one of your folks acted negligently, then your entire operations manual (You do have a manual right?) will be called into court. I have been a paramedic long enough to know the pitfalls of "helping". And since this would theoretically be a paid gig, then you are not so protected by Good Samaritan laws. I don't mention this to be a downer, but I want to make sure you have thought about the liability and you take steps to protect yourself.
As for the radios,You would certainly NOT want to rely on FRS or CB. As I wrote about earlier, they are not going to give you the range needed NOR the professional appearance you need.
What I would do if I were you = I would FIRST, get a UHF frequency pair licensed by the FCC. UHF offers better penetration into buildings and it is easier to get a frequency PAIR (2).
Once that was done, I would get on Ebay and find some used UHF mobile radios. Currently, Used Motorola Spectras are going for $200-300. Get the 110 watt version (make sure you are allowed to when you get your license). Get your local radio shop to program them with your frequencies, and install them into your vehicles.
Then get one and hook it up at home. Get the highest support you can and put the best antenna you can afford on top. Something like a 4 bay folded dipole or something.
Also find some used handhelds. They are usually very cheap.
Now, if you have your antenna up 30 or 40 feet, you SHOULD (this is speculation only, real world testing is going to let you know if it will work or not) be able to work the mobiles out 30ish miles. There will be places maybe 40 or 50 miles away where you can work them, but there may be places 2 miles away where you cannot. It will depend on many factors. You will also have a few mile range with the handhelds.
This will allow voice discussion with folks, but it will not do any tacking. If you wanted to track people or vehicles, you would need to purchase something like a Mototrbo system where the radios have built in GPS receivers and will actually update position based upon that. NOW we are talking THOUSAND AND THOUSANDS!!
I am wagering that with some creative purchasing and building things like antenna supports, and vehicle installs yourself, you could MAYBE do this project for $1000-1500. That would be a radio at "base", and maybe 2 mobiles. The rest would be in antennas and programming and coax and all of the other random things you need to make radios work. Plus the $500 for licensing fees.
I would personally shy away from the cell phone idea. While cell phones do have their place, they are not really built for this line of work. Too difficult to use under pressure and may in fact be illegal in your state to use while mobile.
But the starting of a business is never cheap. From wages, insurance (vehicle, liability, and employee), work comp, building, equipment, fuel, etc; it can add up in a hurry. However you are coming up with startup costs, just factor in a few thousand for radios and do the best you can. In the grand scheme of staring a business like this, a couple of thousand extra dollars is a very small amount I would imagine.
WM
