Had to be in Portland, Oregon, USA for work last week, but I had a free day there so I went fabric (and book) shopping. I'd found a flier for Fabric Depot (www.fabricdepot.com/) in the hotel, so I checked them out first. They seem to be mostly oriented towards quilters, but that means tons of awesome cotton prints. Their prices are not the best, but their selection is tremendous. Their selection of "Asian Prints" is both wide and deep, and you can almost certainly find something suitable for Wafuku in the color(s) you desire. They also have a huge selection of gadgets and notions for your toy-buying needs.
Each of those scans is approximtley 3"x3" originally. The brown silk was in the "Bridal" section, and was marked down by 60%because apparently nobody wants a brown wedding dress. This will make a great kamishimo, though. The two kikko-print cottons will probably just become kosode. If you'll glance to my avatar here you'll understand the magnitude of this find! The blue kikko is a gift for Lady Hara, so we can "match".