Singers, Kenmores and Elna cams are available, it's mostly a question of price, identifying correct type and you can order almost any from the web within a few minutes. I think feet are available for all models, it's mostly about identifying shank type.
Take a look at
the top of Bernina 730 Record, that's the built in patterns, but no options for separate cams. My 730 has very even, nice, satin stitches. I like these machines. Extra feet are easy to find, can cost a bit, but a couple of presser feet is not going to breake you.
I think all of the vintage two layer cams only work with a fixed stitch width and length, the single layer cams can be adjusted any way you like (both types used on the same machine). If the overlock type sitch doesn't matter much I guess a Singer 319 or a 401 is very nice for quilting. If you ever should come across one in a table or c'abinet, they make the flat beds superb for larger pieces of fabric. There's c'abinets where freearms are partly lifted down to make it like a flat bed too. My Phoenix came with 4 cams, I have not seen any for it yet and I have search a bit the last few weeks. Nothing is impossible but it will take time if any additional will turn; if you happen to see an Adler, Phoenix or Ideal make sure cams are with the machine, feet are easy. Gritzners can take a type of Kenmore cam, there was recent thread on this, there is a series of closely related models, and they seem to share the same cams, and sold under various names.