I can help with bearings…
For most needs, follow examples by the automotive industry; they use tapered bearings for axles. These can be externally greased ala trailer and hub axles, or sealed (maintenance-free). There are three companies that I have dealt with in the past, all fabricating reliable product.
The issue generally is with supply; pick a rep that is prompt with low shipping costs in your neck of the woods. My local SKF supplier took about a month to send me the replacement hub bearings, whereas one supplier delivered SKF seals from half-way across the country in three days. Personally, I enjoy calling up the reps and negotiating with the sales because they often have great insight on matching product with the application and saving a lot of time and expense in the process.Know before Ordering
You will need to spec out your axial load, radial loads (static and dynamic), maximum shaft speed, maximum temp, ID (shaft diameter), OD, and allowable thickness (affecting cup design). It’s a little bit cumbersome with the wide selection, though I would lean towards both Automotive and Fuel-Efficient designs. Agreed that you will want the sealed bearings.
Regardless which manufacturer you select, I am certain that tapered bearings will suit your design well for precise positioning
Good hunting, KF