Fergus is a rare first name for males but a very popular surname for all people (#14813 out of 150436, Top 10%). (2000 U.S. Demographics)
Which version is better?
with its variant forms and related boy names. Prominent variation forms of Fergus (not ranked) listed in the Top 2000 are Ferris and Farris. These forms of Fergus were at the height of their popularity during the years 1910-1919 (average #1041). (2015 Birth Statistics)