In this space sooner or later you're going to cross paths with the 3D
printer community. Others exist, but the majority seem to be settling into
either the Allegro A4988 or the TI DRV8825 based drivers. The 8825 has a
little higher current capabilities. (both more than you're asking for)
Here's as good of place to start as any:
https://www.pololu.com/category/120/stepper-motor-drivers

Pololu is a good company (satisfied customer) but be aware that these
designs are open source, clones of these modules are available for under $3
US and the driver chips themselves are available from normal channels.

These are current controlled PWM microstepping drivers and in general you
want to use them with a motor with a _low_ voltage rating as that also
(mostly) translates into lower inductance and lower resistance which
results in higher maximum acceleration and speed - which may or may not be
important to your application. The old adage applies: better to have and
not need than to need and not have.
Current can be set with a resistor (and I've seen at least one version that
used a digital pot) and microstepping can be set with a couple logic lines
(usually jumpers)

As to your end stop question: depends on what you need.
Optical _can_  be very accurate. It's subject to dirt, dust, ambient
lighting, etc.
Mechanical can be pretty good. It's subject to a limited cycle life and
dirt/debris can still mess with it.
Magnetic with reed switch or hall sensor can be pretty accurate too. Many
people overlook the fact that magnets have a field strength vs temperature
effect.
Industrial proximity sensors (inductive or capacitive) are a pretty good
solution too, Tend to be _much_ more expensive, but much more rugged too.

It's been said before that "engineering is the art of compromise." No
solution is perfect, some may meet your needs better than others.

-Denny
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