Take your panel to the fabric store and buy a few coordinating colors, solids or ToT, and make 9 patch blocks any other block you like in a coordinating size. Pinwheels would like nice too. Measure the pictures in your panel and find a number that will go evenly into that measurement (9 and 18 divided by 3 or 10 and 18 divided by 2) then make coordinating blocks in that size.
Sorry if it sounds like I'm talking down. Just trying to make my idea clear.
Love your panels.