I absolutely love your fabric choices. I have always loved using polkadots with florals, etc.
I think the strips depend on what you want to emphasize. If you want to have the blue stand out then use a blue strip, if you want to deemphasize the blue then pick a warm color. Cobalt blue sounds brighter than the colors that you have in the quilt. Using cobalt might be a good way to pull in the wall color.