Reliable reception of the local signals does not require a large antenna. In fact, you could opt for a simple non-amplified indoor antenna for each set and avoid cable runs and splitters.
http://forum.tvfool.com/showthread.php?t=2828
If you want to mount outdoors, any of the 7-69 or 7-51 antennas pointed about SSW will work well with no amplifier needed. (RCA ANT-751 up to Winegard HD7694P)
You could also opt for a larger system if you wanted more than just the local signals... more info if you're interested.