Can anyone offer some help with the Bannantyne/Ballantyne (name was changed) from Strathaven, Scotland?

We have completed so much of our family tree but this one section is still a mystery.
We know of a John Bannantyne who married Janet Freebairn..........both of them from Scotland. They had a son named David Ballantyne (name changed at his point) who was born Oct 27, 1760 in Strathaven. We don't have any info on his parents, John and Janet, other than their names.
We know that David Ballantyne (their son) migrated to Nova Scotia and founded Ballantyne's Cove.
Would love some additional info on this family. ANY help would be so very appreciated!!!!