The amt r series is the best starting point. The engine and gearbox from the dm600 would be the accurate part of the driveline. You could alter the dash from the DM600 to right hand drive. The road warrior has a steel dash and a narrow cab. You could narrow the cab or order a different cab and hood from aitm, or modify the dm600 cab with the front part of the amt r series. Hopefully this helps.
Ben