If you are feeling adventurous you can make your own using quilt blocks from quilter's cache. http://www.quilterscache.com/QuiltBlocksGalore.html
You just have to make sure your blocks have a common denominator, usually 3 because so many blocks finish at 12". You can make 3", 6" and 9" blocks to go with the 12" and piece together and no reason you can't go bigger on some like 15" or 18". Do not under estimate the power of filling strips and units like a FG unit that is evenly divisable by 3 (if that is the number you choose). Graph paper is your friend in these cases.