Molly,
I am a Guest researcher; as such I carry variations of spelling that include Gist, Guess, and others. I don't have the primary docs you seek; my research is a summation of research by others. FYI, I show a Benjamin Gist ca 1720, son of John and Marie DeBoa Gist. In abt 1749, this Benjamin Gist married Mary Jarratt in Lunenburg Co VA.
Possibly related, I'm planning an event Honoring the Rev War service of Benjamin Guess/Guest b 1757 Faquier Co VA, son of William & Susannah Howard Guest; served in NC Militia, was in Battle of King's Mountain with his brother, Capt Moses Guest, under Colonel Benjamin Cleveland and General Rutherford. This Benjamin Guest died ~ 1841 Fayette Co AL, buried Tidwell Chapel cem. Event date is 2nd Saturday in May, 2015, beginning 2 PM (Sons of American Revolution sponsored event).