As for the fabric requirements, you can make them any size you want.
The finished blocks I used ranged anywhere from 9"-10.5", depending on how big you cut the middle square (I based it on the type of fabrics I was using).
So if you cut the center 6.5" and the strips 2.5", you'd have a finished block of 10. Figure for a king-size quilt you'll need at least 100 blocks. Great thing is you really don't need a border.
And since you're going for a much more streamlined, modern look, you'd need at least 5 yards of the background fabric AND 5 yards worth of fabric for the "color" pieces.
Each strip of fabric WOW will be enough go around one block (with some leftover).
Once you get the pieces are cut up, the sewing is a breeze.