For backcountry community radio, it is best to use a radio with dual channel monitoring like the Rocky Talkie Expedition(5 watt) or BCA mini-Link, if you will be using radios for group communications. The feature rich Rocky Talkie Expedition(5 Watt) Radio has the best dual channel functionality, but is heavier than other radios with its larger battery.
Any FRS radio should be compatible with community radio provided it is set to a real FRS channel(22 or below). Unless stated otherwise, all FRS radios are two watts on channels(15-22 or 1-7)
I have personally used a Rocky Talkie Mountain Radio. It is small and clips to your pack strap. It is two watts. For community radio, you can set up privacy code 30 once for channels 16, 18, 20 & 22. When you get to the trail, you only need to use the channel toggle on the top of the radio to select the correct community channel. You can use one of adjacent odd channels for your group channel with your own privacy code.
The High Route gave a glowing review of the new BCA Mini-Link. It has great dual channel monitoring in a low cost package. The review has a great discussion on the use of dual channels for community channels.The BCA Link 1.0(1 watt) and 2.0 are good but, dated radios with only 1 watt transmission and no digital privacy codes. The 2.0 has a separate microphone with a cord and is two watts.
For some backcountry folks, it might be an upgrade; for others, it might be overkill. But, if you want extra transmission power and by default, increased range, dual-channel monitoring, NOAA channels, and capacity to use repeaters, then the 5 Watt Radio it is. – The High Route
There are also VHF radios that support GMRS and allow you to program FRS channels.
Here are preliminary survey results on radio usage
The High Route magazine has good radio reviews.