TheMonkofDestiny: I have the NTSC version and unless I'm mistaken, it isn't region-locked. It was one of the earliest backward compatible titles and most of those were region free, despite the consoles themselves being otherwise.

As far as something like softmodding goes, I won't give advice there since I've no experience with it. The general claim was that it's simple enough to do, depending on how in-depth you want to go (anywhere from buying a copy of Splinter Cell I believe it was, to full-on soldering/etc.)

(edit, as I didn't want to give bad advice about the region: I did some searching, though I imagine you did as well, and it seems that at least in one list that's prefaced with a disclaimer that it's untested, Sands of Time is region free but that's about the only time I can find anything to corroborate what I posted previously so now I'm second guessing myself)

TheMonkofDestiny: It's really strange to me that, given how old the system and those games are that there's no (that I could find, at least) actively maintained and/or definitive list of region free titles. I guess as Microsoft advanced the system and kinda catered to consumers with things like backward compatibility on a surprising number of games, it was just something that quickly became less relevant to most people's needs.

At the very least, in the event the NTSC game turns out not to be region free, I hope it doesn't set you back a great deal of money (assuming you paid for one in the box and all and not just a loose disc).