The main reason I went to NEMA14 for the Z axis was the need to pack the nozzles in tighter. NEMA14 body is 35mm versus ’17 which is ~43.
Ideally my nozzles will be the same pitch as the tape feeders, or the same pitch as the strip feeder tape component pitch- IE 4mm or 8mm multiples. This way multiple nozzles can do a simultaneous plunge and pick without moving the gantry .
I will likely use NEMA8 rather than NEMA11 for the rotation, so weight will drop 60 grams.
Also I have assumed a accel=decel curve for maximums.. but -if decel is to be faster, the stepper is going to have to be bigger, which helps for it to have more authority. This means going to the next NEMA14 up , the 0.22Nm.
There IS a 0.4Nm one, also. You are well and truly into ’17 territory there. A ’17 can do bigger work with a shorter body , but the nozzle pitch suffers. 0.4Nm is approx midrange ’17 territory.
On the DOWN plunge is easy for the Z, because the UP is lifting against gravity. Of course on decel, the opposite applies- lots of work required to slow the payload as the nozzle approaches the Z=0 at mach2.