Normal mileage for the belt change is 12,000. Assuming the 600-mile service was done, valves can wait until 6000, at which time the belt tension should be checked / adjusted as well.

Congratulations on the new steed. I have a 750 myself and would also like to upgrade. I think I'll wait for some used 1000s to come on the market though. Maybe then I won't spend piles of time and money trying to get a few more ponies out of the thing.

Please post some more on what you think of your 900 - riding impressions and such.