Them, not reaching their full size, in a home aquarium is completely false. At the very minimum, if given the proper habitat, you're going to have an 8' Moray on your hands.
And, just to be on the safe side, I'd call the Baltimore Aquarium and ask, beforehand, if they'll take it...99.999% of the time, public aquariums WILL NOT take animals due to not having enough room and also worrying about diseases.
I'm not saying that you wont give this guy a good home, for the time being, so please please dont think I'm directing this towards you personally...trying to say you wouldnt take care of it. I just dont want you to be stuck with this monster and have no means of upgrading to a tank large enough and then the specimen be stressed, get sick and eventually die, if someone such as myself, can give it a proper home for it's entire life.