I'm thinking any model 15 will do very well, as long as a basic low shank has enough space under the presser foot, it will handle anything. Speed control varies a lot from machine to machine, I have a belt driven 201 I am very happy with (single belt external motor in the back), basic button bakelite controler and speed regulation is fine.
15 clones turn up all the time, I'm sure one or two will turn up in your area withing a week. If you are interested in model 15 and it's derivatives, you should include two Americam made ones too, 15-91 and an early model 15 with out the reverse lever. They are very nice points of referance to any other make. Issues with speed control can usually be sorted out with either adjustment of the old or getting a new. These old straight stitchers get very far with the basic motor, noticeably more so than zigzaggers for some reason, and there's always the option to fit it with a stronger motor.
Pfaff 30s are quite strong too, they have motor with more amps than the basic 15 clone, but alas, not Japanese.
Last edited by Mickey2; 09-23-2016 at 11:41 AM.