You can own any Radio you want, however where you transmit is depended on your License that you acquired,
and the max aloud TX/wattage allocated in that frequency range. Most unlocked radio's like the UV-5RM are ham radio's that will transmit in the GMRS band. However the TX Power will exceed what the FCC allows for GMRS band.
You can program any radio you want to frequencies to your liking, but again transmitting on frequencies your not licensed is against the law / FCC regulations. I am not promoting to transmitting with more Power but I have yet to see the FCC knock on your door because you were transmitting instead of 0.5 watts you hit 2 watts. FCC has better things to do. The FCC will come knocking if there are multiple complaints of you interfering with neighbors ( alarm system, TV, and possible other electronics).
Just my 2 cents..
Have fun.
