The radio's on sale don't have the sub channels, but the two radio types will mix, the only thing is a radio with sub channels will have to be set on a channel-0 prefix ie if the one type of radio was on channel 7 the one with sub channels will have to be on 7-0 to be compatible Edit
Most of the FRS radio's that the guy's had for the trip down last year didn't have the Sub channels so it is not all that important so the ones on sale at Bell World would work. Right now 2 for 89.99 and the come with a free cooler bag.