McCallig family in Donegal

Hello,

I am researching my ancestor, Charles McCallig (McCallick in U.S.) who was born in Donegal ~1835 and came to the U.S. ~1855. There is a DNA connection between Charles and John McCallig of Clover Hill, Inver. It is assumed that John and Charles were cousins, but they may have been brothers.  

Adding to the confusion, Griffith's records in the early 1800's show many Charles and Hugh McCalligs in the north-west area of the county (Dunfanaghy). These are family names for us, so there must be some connection.

While in the U.S., Charles married Mary Rose (parents Jack Rose and Mary Welch). Mary was possibly from Fanaghans, Inver. 

I will be visiting Donegal next week (June 25-30) and would appreciate any help or advice you can provide! Which cemetries served the Clover Hill/Fanaghan area in the early 1800's? How can we learn more about the McCalligs in the Dunfanaghy area? There are current McCalligs in the Killybegs area who I think are related to the 1800's Clover Hill McCalligs. Any suggestions on making contact with them?

Thank you for your help! This is a once in a lifetime trip and we hope to make the most of our time in Donegal.