Upgrading a Spectralight lathe and mill

Hi,

I have a 1980's vintage Spectralight lathe and mill that I would like
to upgrade.

These systems were designed around the Sherline lathe and mill. For a
computer, they used an Apple II with a separate box for the motor
drive system. For motors, the system has Superior Electronics
M062-CF-401E NEMA 23 steppers which are rated for 125 oz.in. at 4.75
V.

What suggestions would the group have for how to upgrade these systems
to more modern electronics and software? I consider the Sherline lathe
and mill to be adequate for my usage but would like to hear any
suggestions as to whether one should upgrade to stronger steppers.

I consider there are two avenues available. First would be to upgrade
both the computer, software and drive electronics. Second would be to
upgrade only the computer and software while retaining the drive
electronics. Any suggestions are welcomed in how you think I should
proceed. As for upgrading the software, I would be interested any
suggestions with which company to go with.

Thanks In Advance,

Too_Many_Tools