What the Wizard posted is spot on! I have many of each fabric, and also a few fabrics that he didn't cover. ie cotton and cotton blends, wool blends, polyester blends, rayon blends, and linen.

The fabrics I list above are not readily available from most kilt makers. One must special order or buy the fabric and supply it to your kilt maker. Cotton fabric kilts are readily available in "modern" kilts.

Overall weight and thichness contribute to the swing, regardless of the fabric. Also, some fabrics are just more flexible than others.

But, in regards to you initial question: PV would probably a better choice as a wool alternative, if price does not enter into the question.