Actually, we could have a cloud-in-ac costume..
We could probably edit the color on yuffie's arm-guard, and plop that on Cloud, as well as make Cloud's uniform darker. Of course, that would end up looking lame becasue yuffies arms are significantly shorter than Cloud's.
So, you could try it, but, it won't look good until we have a reliable way to edit the size and shape of the 3d models.