In Celtic lore, Fergus was the ideal of manly courage; Fergus is a charming, slightly quirky Scottish and Irish favorite.
As a name, Fergus forms a link between Ireland and Scotland, as Gaelic tradition has it that Irish Prince Fergus Mac Eirc and his two brothers crossed the sea and founded the kingdom of Argyll in Scotland, thereby making this an excellent choice for parents of either ora combined heritage.
Fergus has often popped up in children's literature, such as in Thomas the Tank Engine and Friends, and is the name of one of Shrek and Fiona's triplets. On a loftier level, there is the Yeats poem, Who Goes With Fergus?
With the nickname Fergie having been appropriated by two high-profile females, we'd opt for using Gus instead.