First, I love the treatment of the Texas(radiant?) star pattern and the colors your picked.
I would audition the white border and make sure it doesn't detract from the white already in the quilt before cutting any fabric...
Another idea might be to finish the on-point pieced squares you have at the top and bottom (you could throw some interesting quilting motif in the solid yellow that would come out of that), and then do a diamond-in-square border to finish out the row. (If I were at home, I'd throw this into EQ6 and show you what I mean, but I'm at work on my lunch break)