i'v toured th US extensively with wireless in-ears
500-760mhz

vagas is RF hell

"all" the one arm bandits in big casinos are networked

G band stuff "shouldnt" interfere with each other
...and bumble bees cant fly

your RF environment dictates how far
and how stable your wireless works

i'm using a walmart linksys wireless g
and have had good luck
but i'm not trying to mix 300' away

"N" stuff should be better at least till it gets congested

the simplest answer to the original question is
wireless in-ears

your's [foh] is not mission criticle so a bit
of rf interference is no big deal

and make sure you unlatch
"solo in place" befor showtime

[fwiw]
mh