All (?) of the monumental inscriptions (MIs) in Caithness have been collected and are in print currently from Books From Scotland amongst other places.
There is an index of sorts for these MIs at Index to Caithness Memorial Inscriptions. This composite index was produced by David Ryrie, New Zealand Society of Genealogists (NZSG), NZSG No. 4960, with authority from The Scottish Genealogy Society. There are no christian names listed, but it may help narrow the search. It was created from "Some Caithness Burial Grounds" (in thirteen parts) by A. S. Cowper and I. Ross - see Burial Grounds of Caithness and Sutherland on the Caithness Community web site.
Sara Jayne Donaldson has published an index to burials at Bower, Dunnet, Reay, Bunnahaven and Kirktown.