Love, love LOVE!!! the second one that mimic's van gough's brush strokes. I remember the initial topic and the quilt top itself was quite dramatic and stood on it's own so my first inclination was to do an all over of some sort. But nothing came to me and I liked what Rob described so didn't add to the conversation. But the idea you and your sister came up with is unique, unexpected and totally awesome. I would do the brushstroke idea with a super fine thread like invisifil or Superior microquilter or even Deco bob in a light gray that would blend in. Those super fine threads blend in pretty well no matter what. You could even go with white and it wouldn't stand out but just leave texture.