Schoolroom Quilt - or is that Quilts?

So I finished sewing my half-square-triangles for the schoolroom quilt, then realized that two layer cakes make a whole heck of a lot of really big HSTs.  168 that are 6 3/4" big.  That's a lot of fabric...  in fact, it's enough to make TWO fronts!  I had bought some gorgeous Cuzco fabric to use as the center of the "X marks the spot" blocks, so I think one quilt is going to be six large stars with Cuzco in the center...  but which star should we do?  With the color around the Cuzco, or the white?

And then with the remaining gazillion blocks, which of the four following layouts should I go with?

The two zigzag quilts..  one has the color going up and down, while the other has the color moving left to right.  Either one of those, of course, could be with either zigzag pattern.  Then there's the diamonds. I was aiming for a "warm/cool" contrast here, but I think you lose that in the left picture.  It doesn't help that the point of the colors is to be the whole spectrum.  That means that a lot of my purples (supposed to be cool) have red in them, which is warm...  etc.  I like the diamonds on the right quite a bit.  But do I like it better than both of the zigzags?  Would I like the diamond on the right even better if all the colors were just mixed together and it was "color vs white" as opposed to "color vs white and warm vs cool?"