I haven't played it in ages, but if i remember correct, you can chose it from the main menu, at the options menu, after you have finish the game. I'll have to look my save data to confirm it 100%.
Actually, the voice option is available from the get-go. It's done in the options area on the main menu. Can't really say about the Xbox version, since I never owned that one.
And Japanese voice option was also available in
LoI.
And I'm one who usually says Japanese dubs are great, but I think the ones done for these two particular games are just flatout awful. In my opinion,
CoD's Japanese dub makes the PS1 version of
SotN 's English dub sound topnotch.
As far as
LoI coming to PS3, I don't think I'll actually be buying it. I mean, I have it on PS2, so there's no reason at all I'd even consider buying the same game on the PS3, probably for the typical $14.99 PSN price, when I bought my PS2 copy for $4.99. If it were an HD version, or some kind of special edition a la Persona 3 on the PSN (though I'm aware this version was also on PS2, so not likely), I'd probably fork out the money to buy it. But as it stands, I'd only buy it if I had extra money to burn, but I'd probably use that money on
LoS DLC chapters instead of a game I already have.