Welcome. Well, you'll find a lot of alternatives to wool here, however I doubt you will find a kilt made with the same weight and sway as a traditional worsted wool kilt. Check the forums for different kilt makers and you will find a lot of choices abound. If tartan is your cup of tea, as it is mine, you will find some nice alternative materials from makers such as Bear and Stillwater Kilts.

As for Sporrans and the like, I can't help you there. I've no idea who makes those type of items in anything other than leather.