the parkers are indeed lin as far as i know. usa made. same as gecko (except those are low voltage). lin will wind you a motor any way you like. basically go in and tell them the drive spec and say "i want more low end, but still 150 oz at 2000rpm and they will find the best match in a winding.
i and going to get something in nema34 from lin if its not crazy expensive to match my parker e-ac's.
i didnt know it was 4mm screws. that makes sense then yeah. 283ipm is still a decent target for a cutting speed. you could do rapids at full throttle (360ipm, 2340krpm or 125khz) where it doesnt use near the max torque. i wouldnt worry about the microstepping. all this is happening in the sub .001" range.
you may have also noted parkers torque curves are for microstepping (not sure which level, probably 1/4 step). they full step rating is also provided. the motors are also designed with low detent torque to minimise the loss of microstepping torque. you also have dip switches for waveform control, which all give different performance trades. in other words, they designed these as a paired drive and motor set and its not likely youll see any drifting more than a few tenths in practice at 16 microsteps.