Its quite hard to understand why Elvis wore the Sundial suit throughout the whole of 1977, there were more than one copy of this suit and lord knows Elvis could have had many copies of other Jumpsuits e.g. King of Spades and other suits from 1976 that surely would have fitted him?
I certainly don't think that Elvis faked his death, judging by his health at this time it would seem to fit that he did pass away, if Elvis was going to fake his death he could have picked a better time! there are so many people who where around to confirm his death, hospital staff etc. I think it would be quite hard to hide the fact that you were Elvis and hide away, someone would have seen him, its hard to keep a secret that big