I have heard of the Motorolla Saber II being used I'm not sure how many people in the market use them but that's an option too. Note they've been discontinued and are unsupported though so you're kind of SOL if you break it and have no clue about electronics and stuff like that. That being said, they're cheap as shit apparently (because they've been discontinued and unsupported) and you can find a lot of them from surplus stores and the like.
More info here:
http://www.repeater-builder.com/moto...ber-index.html