I have a 2011 Conquest (not the classic, but I'm thinking the geometry is probably pretty similar), 44cm. My inseam is about the same as yours and I'm maybe a half inch shorter than you.

I actually find that I'm a little TOO upright, but I like to ride a bit with a bit more aggressive position. We're trying to figure out how to tweak my stem angle without it conflicting with the brakes, actually.

I rode a friend's 44cm Surly Cross-Check. Nice bike, but HEAVY!!! She actually did cyclocross for a while on that bike, but now has a custom Seven in titanium. She earned it, as she rides about 10k miles/year.

I would say the two bikes fit pretty similarly. I don't think you'd want to go smaller with the Surly.