Eric, their are two wires that go from a power supply to the radio.
One is positive and 1 is ground.  The radio is protected by a diode to
protect against reversing the wires.
The way it works is the right one.  The other is the wrong.  On the choice
of radios, how much power do you need to accomplish what you want to
do?  How intense is the RFI in your area?
What are your antenna options?  How many bands and which ones do you need
in your area?
What else do you want to do with the radio?