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.
1983 Nighthawk 650
1989 Inteceptor VTR 250
1985 Sabre 700.......Sold
1983 Shadow 500.... sold
2006 Ninja 500........ sold