How did you measure you leg length? Don't use pant size. Measure from snug in the crotch to the ground. Some insist on without shoes, but you'll probably wear shoes when you ride, so that half inch or so isn't a big deal. Now if you got 6" heels, that might be an issue. <grin>

Unless your crosstail is the same geometry as the bike you are getting, then don't try to convert the size into cm of seat tube. Different model bikes even within the same manufacture might have different geometry that makes that seat tube length meaningless.

Otherwise, you aren't any different than the many other recent threads here about fitting. So what is already written still applies. Look at some of the other response in those threads.