I would look for a paisley, or something with a large, roundish pattern that covers all of the background, like this:
https://www.fabric.com/buy/dg-047/ka...-chrysanthemum using colors similar to your top. Here's another:
http://demandware.edgesuite.net/aamm...23/2305472.jpg
The roundness and busyness will provide a nice contrast to the calm color palette and straight lines of the top.