J. Ahola sang the hell out of "Heaven and Hell" probably one of the best vocal covers of it that I have heard. And Rob Rock can sing some fucking Dio, check out his cover of Last in Line.
He was part of a Dio tribute in Orlando shortly after Dio passed. I believe it was at the same venue seen in that video above.
Those who don't know who he is by name will recognize him from some of the better Avantasia songs (Sign of the Cross, Glory of Rome, Neverland).
Russell Allen would be appropriate to I think. And though he is a douche, Sebastian Bach probably.
Damn with all the Ripper hate. Seriously. The dude can sing, and he always seems to get tossed aside like trash. I like Iced Earth, and I liked Matt Barlow alot but Schaffer pretty much threw the guy out like last nights garbage. And I saw him live when he was with IE and he was a stellar live singer, better than Barlow actually.