You need adaquate standover clearance, at least 1" or 3" for compact style sloping frames. Given that clearance, the more critical dimension is length. You need the bars in a comfortable position which you get with a combination of top tube (TT) and stem length. Excessively long or short stems affect handling. 10cm is about the std length and you can usually alter it +-2cm with no ill effects. Pick a bike with a TT length that allows you to use a 10cm(ish) stem where the bars feel good, not too extended or cramped.
Take a tape measure to the shop for comparisons. The dimension you need is from the nose of the saddle to the grip part of the brake hoods.

Many fitting guides make assumptions about how you want to ride. This one doesnt.