Does anyone have any experience in having a memorial headstone or plaque installed in an Irish cemetery?

I believe my great grandparents to be buried in an old cemetery in Co. Sligo that has not been used since the 1930's but no stone remains.

I would imagine I could start by contacting a local funeral home but wanted to see if anyone had any suggestions or 'do's or don'ts' they'd care to share before I started. I am in the U.S.
Thank you.