In the guild I belong to we do a lot of strip quilts on the diagonal, you can then put them together in different ways or you can cut them in half and have a whole new design element.
Are there any quilt guilds near you? We get too many donations of fabric that we cannot use. We are not accepting any at this time because we don't have storage for it all. We had a yardage sale and made over $600 and sold the fabric for $1 a yard!! You might check with them to see if they are willing to pass the fabric along to you. Advertising on Craigs list for fabric donations for your cause is another way? Perhaps??
I think what you are doing is fabulous!!! :^)