Khan--Are you kidding me? Have you heard this guy on the last two Kamelot tours? He can't even handle a three-month tour performing 90-minute sets! His voice wouldn't exist after performing 2-3-hour shows on the road for a year straight!
Lance King--I personally like Lance as a singer. However, I don't exactly think of power when I listen to him. Zod, it kills me that you absolutely love Lance yet abhor James. They certainly have their differences, but I think they have a similar approach to the high end. Anyway, Lance isn't quite as diverse as James. He has a specific sound to which he likes to stick, which suits me just fine as a listener. He'd sound great on stuff like "Under A Glass Moon," but do you think he would sound just as convincing on "I Walk Beside You?" I doubt it.
Russell Allen--One of my favorite vocalists. He would come close to pulling off the different sides of Dream Theater's music. He would give the heavier songs even more balls, and he can match the emotion of LaBrie on the lightest stuff. However, I cringe at the thought of him behind the mike on pop-influenced songs like "Prophets Of War." Besides, I don't think he'd hold up so well on such a lengthy touring schedule.
Mikael Akerfeldt--Now I know you're kidding. Anybody who wants to claim that LaBrie sounds too breathy when he's singing ballads couldn't possbily, in a perfect world, be a Mikael Akerfeldt fan. I've never heard a weaker singer for lighter music in my life! Mind you, I've seen Opeth three times, one of those times being for the "Damnation" tour with Porcupine Tree. Akerfeldt has no range outside of the half-octave represented on the sung portions of Opeth's songs. Other than that, he can growl. How would growling work with Dream Theater? I have two words for you: it wouldn't.
Michael Eriksen--I think he would be the best fit for Dream Theater out of all of the singers mentioned. His range is excellent, his tone is very pleasing, and his delivery is full of emotion. It's really just a matter of how well he could handle the constant touring.