Thanks for your answers.

Which plan do you think makes more sense?

A) original height (for short reach)
frame size 47 etc.
extra spacer
high seat
maybe crank size 170 to 172,5 or 175

B) new height (for high stack)
frame size 50,51 etc
short stem (32mm etc.)
high seat (maybe middle)
maybe crank size 170 to 172,5 or 175

C) ???? (your plan)

thank you all.