The NC9RS Group has alot of information available HERE
I started out using the Motorola GTX Handie talkies and mobile radios. They do not require any hardware modifications..
The Motorola Spectra is also a nicely built radio, This requires only a single resistor added to the VCO circuit. The only problem I've had with the Spectra is the Electrolytic capacitors usually are leaking and require repair. Not a hard job but it does require soldering some surface mount
components. There are even hams who will provide this service for a fair price.