Thanks, everyone, for the good suggestions. Feline fanatic, I feel honored that you couldn't tell I am sort of a beginner. Yes, I did know instantly that I could not do a bargello. :)
I was going to take a few days off of quilting, but I find myself already auditioning fabrics for the borders. I have actually been quilting a bit over a year, and so far my borders have not been wavy...probably because I measure the center before I cut my borders...learned that from my sister, who HAS been quilting for years.
I don't need to make this quilt larger, but I like the look of two borders, so that is what I am leaning towards.