Don't bother too much about the old type tensioner, you will soon get used to it. The easiest way about it is to do a drop test to get the bobbin tension right (bag of beans or rice), then adjust the upper tension nut until you get a balanced stitch. It's easy once you get used to it. Unless you switch between thread weights a lot, you will get by with one bobbin case. It can be a help to have one bobbin case for top stitch thread, and one for sew-all weight. Bobbin tension is more fuzzy to adjust.