You are the same height as my gf, who has a 27" inseam. The problem for her is that, like many women, she has relatively long legs but short torso and arms. So seat height is not a problem, but top tube length is and she needs a very short stem. I'm 5'-3" with a 28" inseam, and ride a 49 cm frame which is just about right for me. So you can make do with a 49cm if you use a super short stem, but would probably be better off if you could get the smaller frame, which will have a shorter top tube.