The Sailrite is a cool design, it looks like a Consew 146RB1a and a Bernina 217 had a Baby ...LOL .
If it just has to be a Portable, for a ZigZag option ? , Then get a Sailrite like Riggerrob suggested . It a little smaller, with 7"on the work area than the standard 10" industrial, but totally makes up for it on their whole self-contained portable package design.
It's a combo straight-stitch/zigzag . It's feed is walk foot, strong puncher for it's size, and probably the portable sew with most needle punch power sold .
The old pfaff 230's are around for a lot less-$ than Sailrite, and good for a lightweight fabric stitcher .
If not need portable package, maybe look for a old Singer 20U zigzag, singer made a million of them, I see them around for sale on the Craigslist here once in while, and always pretty cheep-$ .
Also look for the old Singer 143w strait-stitch/zigzag. I used to have one of those and they are old but 'strong' built model.
.
.