Refering to the information in several of my quilt history books different kind of stitches had been used for quilting in former times. One famous example is the 14th century quilt from Sicily, now in the Victoria & Albert Museum in London: it's quilted with a backstitch. I think you should be aware that the back side of your quilt can look different to the top and the quilt is not reversable. Maybe it would be an option to combine embroidery just done on the top with "regular" quilting with the running stitch? Just a thought...