Never heard that before. While he'd be certainly theatrical enough for the role, I think that George Takei would have the better (i.e., deeper) voice.
while Takei
does have a deeper voice, i don't think anyone would be able to take Vader seriously later in history, assuming Takei goes on to everything else in his life, especially becoming a facebook star (Takei is awesome, btw

). unfortunately, i don't know many other actors from the period who could conceivably voice-over Prowse (or whoever else) as well as James Earl Jones. the only one that occurs to me is Kevin Michael Richardson (probably best-known for voicing Captain Gantu in
Lilo & Stitch, but he's all over the place in voice roles, much like Steve Blum) but he was only thirteen at the time of Ep4's release IOTL, with his earliest role being on
The Simpsons starting in 1989
wait...an idea occurs to me...
if
Star Wars is delayed a few years, then Kevin Conroy could voice Vader. think about it: at the end of the Original Trilogy, the Joker beats down Batman with a lightsaber
