I'm searching for my Beacom ancestors as well..
Isabella (my g-g-grandmother) born c. 1834, her sisters Jane born c. 1840 and Margaret born c 1842, parents John and Rebecca, nee Mitchell.
Isabella states on her marriage certificate (to Thomas Hewson in Ararat, Victoria, Australia in 1870) that she was born in Tyrone and that her father John was a farmer.
There are two farmers listed in the Griffiths Valuations, one in Relagh, Kilskeery, Tyrone and the other in Glasmullagh South, Kilskeery, Tyrone.
I've emailed Mrs Jean Beacom at Corick Country House too to see if she can shed any more light on them.
Any other information would be gratefully received. Thanks!