I've never seen a radio equipped truck except the FMTVs. the MTV cab can host a radio behind the passenger seat either mounted on the storage box or on the wall of the cab. Antennas are mounted on the backside of the cab. I guess if you really needed to you could mount to the bed or bumper, but I've never seen that.
I have seen some HMMWVs tricked out with antennas for VRC sets. I think commo had one with 4 or 5 antennas on a soft high-back. The newer shelter variants have some awesome foldable antenna mounts.
MRAPs, specifically the Maxx-Pro variants, can be seen with Antenna mounts on the bumper.