sUAS operations conducted under Part 107 are not subject to the equipment requirements of Part 91 for manned aircraft pilots, meaning that unless your airspace authorization or waiver paperwork explicitly requires it, you do NOT need to purchase a handheld radio.
That said, having a radio to tune into local airport broadcasts and aircraft radio chatter may help provide stronger situational awareness, particularly to those of you operating close to high air traffic areas.
To actually transmit over a radio requires a separate FCC license, and the FAA’s position is that sUAS crewmembers should really only use a radio for monitoring purposes, not for transmitting purposes.
To those of you who are in the market for a VHF radio, here are a few recommendations:
And more recommendations over here: