agree, a 16 should be spot on. I'm 5'10", ride a 16 456 ss with 50mm stem for almost all of my riding, from long xc days to messing about on local steep techy stuff. Its a wicked bike, bought a year ago when they first came out to stop my blur 4x bearings getting murdered over the winter and ended up selling the blur frame cos I was having so much fun on the ss. Do use the u-turn on the pikes a bit, the head angle is too slack with the forks at 140mm for steep climbs but its worth it to have it choppered out for the dh's. If you're worried about not getting enough xc-stretch then perhaps the standard 456 would be a better bet. Sounds like you want the ss, so should go with the smaller one for a more chuckable bike. Long answer to a short question!
Oh, and can't remember how long it took to ship, prob less than a week. Thats a question best asked to on-one I reckon.