OK, Lira, I did my homework. The 50 cm Lexa has a short seatpost (about 290 cm) and the the total stretch (top of saddle to top of extended pedal) with seatpost fully raised is about 82.5 cm. At this position, the handlebar at its highest position is about 1 cm lower than the saddle. This is short of my 85 cm rough estimate, and although it might work it gives you no wiggle room.
So I looked at the 52 cm Lexa. This size raises stack by 1.6 cm, is equipped with a 350 mm seatpost, and stretches reach by only 3 mm. It's shipped with an 85 mm stem, while the 50 comes with an 80. The total stretch is 89 cm, which amply covers the wiggle factor.
Some months ago I looked through the online catalogs of the major brands to compare WSD geometries. I found Trek's Lexa and Silque to have the tallest stack dimensions relative to the reach dimensions. That is, these cockpits are the tallest shortest you can buy without going custom. So Lexa seems to come the closest to addressing your priorities.
My recommendation is to order the 52. Your leg length requires the stack height, 3mm of reach is almost trivial, and it can be accommodated with a stem swap. Keep an open mind about the 85 mm stem, but if it isn't right, have it swapped for something shorter. Get a commitment from the dealer to get this to fit. He sells Trek so this shouldn't be too hard. This stem comes as short as 60 and 70 mm (which are currently out of stock at Trek). Regarding initial setup for beginners, I recommend setting compact flat-topped road bars level with to a couple centimeters lower than the saddle. Proportionally longer arms indicate going lower, and I'll go higher if the rider has physical limitations or simply insists on it.
And here comes my disclaimer. I'm a mechanic in a shop that primarily sells Trek, so I feel some responsibility for your satisfaction if you do end up buying the Lexa. Good luck.