I'm a huge fan of scrappy quilts, and also of fat quarters. I have yet to find a pattern that calls for yardage like yours (x yards of light, y yards of medium, etc.) that won't work beautifully with fat quarters. I tend to start such projects with quite a bit more yardage than they call for, because I want it even scrappier. Why settle for eight light fabrics when I can use 20 or 30?