If your cycling inseam really is only 30 inches, you are probably going to need a smaller frame with a longer stem just so you can stand over it without racking your junk on the top tube. I'm 5'5" tall and I ride a 50 cm; even though I am 7" shorter than you, I have a 28" or so cycling inseam. I would be surprised if you can stand over a bike that is bigger than a 54 cm, unless you've mis-measured yourself.
Fortunately you should have no problem finding a used 54 cm bicycle and installing a longer stem to get the proper reach. Or you could view it as a bonus if you're not too crowded in the cockpit that you'll be a little more upright with your shorter legs/longer torso and wait until you're a little more flexible to push your handlebar away from you with a longer stem.
Given that your size is going to be close to what many bicycle manufacturers call "medium," you should have no problem finding a used road bike.