This would be really easy to draft yourself for PP. Say you want to finish at 10". Draw a 10" square and mark the center point on each side. Draw a second square inside with each corner of the square touching your marked center points. Draw a 1" border inside that then mark the center points of that square. Continue for the next inside round. Once you have it drawn out you have your PP pattern. You can make multiple copies by gluing 4 or 5 sheets behind your drawn piece. You only want a drop of glue to keep the papers from shifting, then sew with an unthreaded needle through all sheets using your drawn pattern or you can go to an office supply store and make copies.
For your background I would use the same fabric for each block but if you want to mix and match for the other blocks I think that would look great proved each background is the same value of black/white/gray print.