rtciv, Measurment to the top of the seat tube don't help much, sorry. I have a 33.5" inseam and presently ride a 56 cm roadie and a 23" (~58.5 cm) touring bike. Top tube length is a more critical measurement IME than standover and my two are within 1/2".
You're probably fine with something in the 58-62 cm range, but hands-on testing and an assesment by someone knowledgeable is the best route.
Brad