I would recommend a Vintage Kenmore. They are serious workhorses. You want a model 158.___ They were made by Jaguar engineers, and are "bullet proof." You want one that has a low shank presser foot, so you can use any standard snap-on foot. You want one that has a front-loading bobbin, not the drop-in or side-loading bobbins. And you want one that has built-in stitches, not just cams.
I collect vintage Kenmores and Berninas. They are my favorites. I also have a couple Singers and a White rotary, etc.