I love the quilt, so "Navaho" looking. Have you auditioned different colors for the thread? I was wondering how a darker cream color would look, since it is in the print fabric.
A stipple would be probably one of the easiest, or loop de loops. No rules there. Keep in mind that FMQing the quilt is going to be considerably more challenging than the practice pieces, due to the weight/drag of the quilt.