You have two options: You can use those decorative stitches thru just the pieced top or assemble pieced top with batting and backing and stitch thru them all. You can also use a heavier weight thread and get some amazing designs. Use a 90/14 topstitch needle. Most of all - experiment.
If stitching thru just your fabric top, you should stabilize it w/ several layers of spray starch and a fusible, medium weight interfacing. The layers of a quilt sandwich are stable enough to handle this type of stitching and don't require stabilizer.