Sizing help please... Interested in a birdy, but cannot get sizing info. Searched and found that effective top tube was 58cm but position of bottom bracket made the bike a "medium" size.

On road bikes, I ride 58cm (C-C) seat tube; 57.5 cm top tube, and 110cm or 120 cm stem. I'm 6 ft. Would I be cramped on a Birdy (sit too upright)? Are their options on stem/handbar to stretch out a bit?

Many thanks in advance.