FWIW, I've got the Nikon 60mm AF, 105mm AF, 105mm AF VR, 200mm AF and the 70-180mm AF Zoom micro lenses as well as the PB-6 & PB-E bellows set.
The suggestion for getting a reversing ring is an excellent one. It is a good inexpensive way to get high reproduction ratios.
If you decide to get a true macro lense I would suggest the 105mm as the first one and to get higher magnification get a set of extention rings. I find I use the 105mm the most then the 200mm.
If you really want massive magnification you could get a bellow set but you they are pretty much just for studio work. Very hard to take them into the field.
I am still shooting film with a FM2n and a F5. I do not use digital cameras but I do have a scanner for my slides and negatives.