The range for these radio really depends on the terrain, it can be a few hundred meters or as Dang says a lot further. We have used the Motorola ones (TLKR-T3 and T7) with the kids when camping and on the beach, as it's easier to say 'come back for lunch' than to keep shouting for them (3 kids & 2 of us).
Some have sockets for earpiece/microphone which might be useful if you are cycling with them: the T3 didn't but T7 did (but didn't come with the earpieces).
I think all are 8 band, but then the ones that say they have 100's of channels use electronics to create sub-bands. You still can only have 8 users across the bands. The sub-bands help to make the talking less public when people select the same band. You can mix different handsets and they should work. At worse you will need to select one of the main 8 bands and sub-band 0 (if it uses sub-bands).