what official matters?
Last i know, Japan and Taiwan uses seals. But not really the
practice in Taiwan now unless on official documents.
But as far as i know, your seal have to be registered with their
seals office.
Anyway, in chinatown many ppl carve seals, just a 20 mins service.
you can get seal and carving for aronud $50.
But if you using it for official matters, do find out the approved
script.
If you used ancient script, it might not be accepted.