The walking foot is really only good for straight line or very gently wavy lines. I would suggest that if you are planning on putting embroidery on a quilt, you might want to do it before you sandwich. The embroidery will 'take up' fabric and you run the risk of puckering if you embroider after. Hope this helps and makes sense.
To answer the question of which foot, probably an applique foot or if you have an embroidery machine, mine uses an embroidery foot which kind of looks like a hopping, or darning foot, like you would use in free motion. Check your manuel for the best foot for a particular stitch.
Last edited by mike'sgirl; 08-12-2014 at 11:25 AM.