I have a 990 R and are planning to do the TAT this summer. Any suggestions on the best tires for the trip? I've gotten conflicting reports. Some feel the stock rear Scorpion wirh a nobby on the front would work best. Others say replace both with a true off-raod rally class tire. Any suggestions on best brand - Mefo, Pirelli, Continental, Heidenau? Any feed back would be appreciated.