Seems that the white boarder is the most popular. I agree. It will give it a nice clean look.
For quilting, I tend to choose the opposite of what the quilt pattern is. For instance, if it is a geometrical, straight pattern (like yours), then I like to choose a curvy type quilting top stitch. If the pattern has a lot of curves then I usually like to choose a geometrical type top stitch.
Opposites usually make the other look good. This is not an exact rule, as there are exceptions, but it is what I tend to do.