I haven't seen any multi-disc changers that include a PAL -> NTSC converter. You might have to get an external converter to satisfy the rest of your requirements, even if they are ridiculously expensive (at least they were the last time I researched them). Of course, you could get a digital TV that accepts both PAL and NTSC instead.
*Doesn't get weird on the tougher discs (e.g. Matrix)
Hmmm, I haven't found a player yet that didn't get foxed by at least one DVD.


