Rather than going by the manufacturer's frame size, I recommend going by top tube length. You can use a bike size calculator here:
https://www.competitivecyclist.com/S...ulatorBike.jsp
with someone to help you take the measurements. Saddles go up an down a lot, but there's a relatively narrow range of stems which feel good, and everyone's proportions are different. You can't really go by height or inseam.