I'm looking at getting my wife a dirt bike to learn how to ride on. However, it needs to be a bike she will not quickly outgrow (i.e. xr 100, etc..). It needs to have a fairly short seat height as she is only 5ft. 5 in. tall. It also needs to make decent power in stock form, as we live at 6000 ft and often ride at 9000ft. Any suggestions?