I'd use a dark brown 1" wide frame to contain all that lovely color, then a 4.5 inch border of your favorite brown from the quilt. Trying to border it in the light blue would wash it out, IMO.
I was going say to say a quiet print for the wide one, but I used a huge print and a coral binding for my busy Fandango quilt and it was wonderful. Yes, I did use a brown first sashing to contain the colors. I hate to post a picture - it looks pink when it is coral. I didn't get a finished picture. I'll have to have my daughter take one.