I also vote with the available light guys,,, all the light available that you can carry;-)
Focusing rack, depending on subject matter, there were some plans years ago that included some electrical alligator clips on heavy copper wire with a camera mounted on one end. The agriculture folks used something like that for field photography of various smallish things with a ring flash.
Not sure we get to talk about focus stacking on this forum. If the subject is "fixed", you might look into that for DOF control.