I've used a twin needle to quilt, not caring that the back would have a zig-zag ... but it WILL. Without a double bobbin (does any machine have a double bobbin?) you can't get away from the zig-zag on the reverse.
The craftsy site doesn't have a good picture of the reverse. You can only see a single line of stitching.
This video shows you what the reverse looks like.
http://www.howcast.com/videos/512586...ewing-Machine/