So - if you need an average sort of length - 24 inches, plus a hem, you could get three widths from the 78 inch piece - if the fabric is 1.5 yards wide then you would have 4.5 yards of kilt there, minus the seams to join it together.

You can then cut three more pieces from the 96 inch length, leaving 18 inches full width to cut the two waistbands, belt loops if required and the pockets. That might be a bit tight - but do able, I think.