I think I'm gonna do a 3" border that matches whatever colour it's next to, (purple border next to purple pieces, yellow border next to yellow pieces, etc) that way I can use up the rest of my fabric, and then another 3" solid black border all around.
I'm not too sure about the quilting, though, I don't want to ruin the effect by making the quilting too intricate, but I can't stitch in the ditch to save my life, so I'm kinda stuck, lol! I'm thinking of using transparant thread so it doesn't interfere with the pattern.