Opinions wanted: 408/416 Stroker or 440?

"I have been told that small blocks can handle more revs and get to those refs faster than a big block."

You've ben lied to. Properly built, either iteration could rev quickly, and reach any heights you want. You're not dealing with "big" or "small" blocks once you start going with non-factory strokes. Those terms will only relate to bolting things in or onto it.