This is pointless.
He changed his middle name legally in the sixties from Aron to Aaron! There is no debate about this at all, so why the poll??!
Elvis was named after his father, Vernon Elvis Presley, and Mr. Presley's good friend in Tupelo, Aaron Kennedy. Aron was the spelling the Presleys chose, apparently to make it similar to the middle name of Elvis' stillborn identical twin, Jesse Garon Presley. Jesse was apparently named after Vernon's father, Jessie Presley, although the spelling was slightly different.
Toward the end of his life, Elvis sought to change the spelling of his middle name to the traditional and biblical Aaron. In the process he learned that official state records had inexplicably listed it as Aaron, and not Aron as on his original birth records. Knowing Elvis' plans for his middle name, Aaron is the spelling his father chose for Elvis' tombstone, and it's the spelling his estate has designated as the official spelling when the middle name is used today.
Similarly, there is some slight confusion regarding the spelling of Jesse Garon's name. Most reliable resources have the spelling as Jesse. However, near the graves of Elvis, his parents and his grandmother at Graceland is a marker the family placed in memory of Elvis' twin, but the spelling is Jessie for reasons we have yet to determine. Jesse Garon's actual grave site is in Tupelo, MS where it has always been, but it remains unmarked by a tombstone. Lack of money in the family's early years was likely the reason. Then, once Elvis became wealthy and famous, the grave, which is in a public cemetery, remained unmarked most likely in the interest of privacy. Because of the spelling on the marker at Graceland, we tend to use the spelling Jessie to avoid confusion.