There are many oils that will work well in this engine, Rotella being one, and none that are clearly superior. And many good filters, including the HiFlo line (HiFlo makes the K&N oil filters).
Be sure the driveshaft spline joints are correctly lubed. I've seen a Suzuki C50 where the splines were dry and ruined. If they aren't in the gear oil, the Honda moly paste does a great job.
For that low mileage 2005 bike, be sure all the fluids have been renewed, even the fork oil.