I've made smallish projects with dupioni silks -- it looks absolutely gorgeous with free motion quilting in an iridescent thread. My tip would be to avoid very small pieces in your design, since silk does fray more than quilting cottons.-- so let the drama be about texture and color more than intricate piecing. I'd also experiment a bit with a bigger seam allowance-- 1/4 inch may be too scant depending on the weave you're working with.
Have fun. I love silk.