I plan to do mine with either 4 or 5 inch blocks, and just sewing the blocks together directly.
I ran a swap on Ravelry recently for 5" squares. Everyone sent in 12 squares of 5 fabrics (so you could cut them out of a fat quarter, we didn't necessarily fussy cut). I ran two groups- so I have 120 squares waiting, and it didn't cost much at all, because I only had to buy 10 fabrics, and I got them on sale.