I really haven't done any Presley research. My ancestor, Moore Lee Porteus, was born in Enniskillen, County Fermanagh, Ireland, and migrated to Pennsylvania about 1818, then later to northern New York State. His brother, John Porteus, married Jane Presley in Ireland, and this family came to northern New York in the 1840s. As I recall, there was a half-sister of Moore Lee and John who also married a Presley, but I have little info on them.
Another thing you might consider - Elvis Presley apparently descends from a Palatine German PRESLER family, according to research by Henry Z Jones, Jr. I hope this helps.