Bringing the Canton Civic Center into consideration is a good move. It's a hockey arena and seats, what, 5,000? It does have one end chopped off for a stage, IIRC. Of course we'd build something far superior to that poor old lady, but that can give a good visual concerning appropriate scale. We'd need an 8,000 - 10,000-seat facility? So half the size of the Q, but twice-ish the size of the Canton Civic Center.
(edit:) With a relatively LOW roof! We need to keep the noise in there! Even the Q is usually pretty quiet (of course the Cavs have a lot to do with that). That's why they NEVER turn that blaring music off! There's ALWAYS either music blaring or an MC screaming. It's IMHO, pretty hokey - needless to say, not a college basketball environment which is more focussed on the band, students and THE GAME!