how do i set them up

I am a big fan of the U shaped spread, but have used an X shaped, too. However, imo you would need more dekes for the X. I would set up some Foots on the points and to cover up your layout using at least one original, and mix in the silos. Put them in family groups of 3 or 4, spacing them out a few feet in the groups (maybe more since you are limited in the number of decoys you have), then move out a little more for another family group. I prefer to keep one kind of decoy together in family groups, as I feel the size difference will be noticeable with a silo next to a full body, so one clump of Foots, another of silos and so on. If you are hunting next to water, you could do a J spread, extending the side opposite of the water.