An RCA ANT-751 mounted on the chimney pointed at 225° would be an easy option.
The traditional distribution method would be RG-6 coax from the closet under the stairs. With HDMI cables already in place you may consider a Channel Master CM-7001 tuner. Centronix, Epivision and Winegard are also potential tuner options. IR remotes would likely be your option if locating the tuners remotely.
Best practice is to use a separate FM antenna and cabling. You have strong local TV signals, I presume that there are strong FM stations nearby as well. That's a recipe for FM interference if you combine the two services on a single coax system.
Another option is to place Home-Theater-PCs next to the TVs. Use the CAT5 to integrate SiliconDust HDHomeRun tuners, Hulu, Netflix, etc. on the LAN.
http://forum.tvfool.com/showthread.php?t=820
http://forum.tvfool.com/showthread.php?t=2882