The Kymco Grand Vista 250 fits my wife, who is short, but with no oil filter, the oil change is about 1200 miles.
But only 1 qt of oil to buy, so it is a cheap change. It does weigh about 330 lbs.
Not sure about the valve adjustment period.
At the low purchase price and the distances that my wife rides, I don't figure to ever worry about the valves.
ExTex: 2015 CB500 FA, 1989 Inteceptor VTR 250
Sold: CB650sc, VF700s, VT500c, Ninja 500