The 401A is considered by many to be the best machine Singer made. I believe it is the best ZIGZAG machine they made. I love the whole 400 series of machines. I don't garment sew and had no need for my 401 or my 403 and sold them. I kept my 404 straight stitcher though.
I have some slant feet around here somewhere. If you are interested in them, I'll make you a good deal, I believe I even have a vintage Singer slant shank walking foot. The 401 has all the stitches built in, you shouldn't need any cams.