I like the gray and white you used for the inside of the quilt. They make the nine-patch blocks "pop".
I do not like the gray print (on the right in the picture) for an outside border. IMO, it doe not match the "feel" of the rest of the top.
I don't have any suggestions for the border - if you want it bigger - and have enough fabrics - you could add more blocks until it is the size you want - and then just bind it.