Okay, this is my third attempt at posting in this thread.
I agree with REG about Michael Weatherly, for many of the same reasons. My only concern about Weatherly, though, is his height. I would make casting Spock more difficult (I believe that Spock should remain taller than Kirk).
George Eads as Scotty? Perhaps...I'd like to see a real Scotsman in the role, though. 
Of course, I was thinking that Colin Firth (an Englishman), has the physical features of a McCoy, although I don't know how good he is at accents.
Davy Jones
"Frightened? My dear, you are looking at a man who has laughed in the face of death, sneered at doom, and chuckled at catastrophe! I was petrified."
-- The Wizard of Oz