You could go without a border, I've seen that, too & it looked great. Myself, I'd put a 1 inch red sashing all around it, another row of charms, then a 1/2 inch red border or go borderless, which would serve as a pantograph guide when you quilt-the-quilt & do a smaller panto on the red sashing - making the quilt back pop. If you made shams to match they would have pattern continuity with the red sashing pattern repeat. Just my random thoughts, nutty me! Please post when you're done, love to see it finished!