I decided what I'm going to try doing with it. I modified one of the layouts to eliminate the half-squares on the edges and just made it an on-point layout. One of the 9 patches just needs a white corner square.
I saw this charm pack on eBay and love the colors and floral so... I bought 8 charm packs of 25 squares for $4.95 each (+$4.95 total shipping).
I figure on using them as 5" squares. I will need 12 colored squares across and 16 colored squares down, for a total of 192 colored squares. 8 charm packs would be 200 squares. I'll get a cream fabric for the rest of the squares. As a rough measurement this would be 90x120 (minus seam allowances). My figuring is 12 colored squares + the 6 cream squares across is 18 x 5 = 90. 16 colored squares + 8 cream squares down is 24 x 5 = 120.
I really hope I got that right!