Well my Halls came from Aughnacloy area too, there are 2242 townlands in Fermanagh and no Killmann! Killernam, Killynamph, Kilnacran are the nearest I can find in Fermanagh. OR you can have Killymann in Co's Armagh (with townlands of; Clonmore, Clontyclay, Derrycorry North, Derrycorry South, Derryhirk, Derryhubbert East, Derryhubbert North, Derryhubbert South, Mullenakill North, Mullenakill South, Mullenakill West) and Tyrone (with 38 townlands) which are both civil parishes.
Aughnacloy is just over the border from Co Monaghan, so it is also another possible.
I haven't comes across Beacom or Mayers/Myers in Errigal Trough which is only 2 miles from Aughnacloy.