You might try the official Triumph site and look under dealers. If there is none there listed you might start praying a lot....and hope it doesn't break down on you.
Second...order the shop manual and be prepared to learn on the fly. If the Rocket has been well taken care of and you don't have any of the "known" problems on the bike, you may be able to get by on just an occasional oil change (every 10,000 milies, using full synthetic only) and air filter changes.
Good luck,
Dennis
6 dtg Dubai