You might try contacting this guy,
Bob Bolland's IDA-72 Rebreather Site he is on Okinawa and dives a converted IDA-72. Below's a picture of his gas storage at his home, I don't
think he uses the LPG in his rig...

but at least it looks like you can get O2 and Helium etc without any trouble.
I don't know if he's active on Rebreather World but there's an email link on his site.
Cheers, Ray.
