Yes, there are "Meridian" phones that work without a system. I believe they were in the 9000 series. Radio Shack sold them for a while (under the Sprint name), but I'm not sure that Nortel makes them any more. They really weren't that simillar to the M7208 though.

As far as buying a system, Sundance has a small Norstar (Meridian has more or less been reserved for the large PBX systems. The official name is now Norstar, though older phones may say Meridian) system capable of up to 3 lines and 8 phones. It runs for $495...but it will need to be installed. If you do not know anything about phone system installation, I reccomend NOT doing it yourself. It will require a fair amount of wiring and programming.

Also, be very careful about plugging in an M7208 straight into a phone line. It is simply not meant to be used outside of a phone system. Phone systems use much lower voltages for ringing and signalling (usually about 5 volts). If a call comes in on your phone line, the rining voltage (90v) will fry the phone.