Getting a handsewn kilt isn't really so difficult, there are lots of us who either part hand sew or could completely hand sew if asked.

The question of hand woven fabric is a lot more complicated, there are actually very few "hand woven" tartan fabrics available, by that I mean the main tartan weavers almost all use mechanical looms, and some of the smaller concerns eg Harris tweed, use looms with mechanical assistance- although technically they can still be called hand woven.
Some weavers will be open to give you all sorts of details about the content /variety of the yarns,, but as said before many kilt makers don't really have a say in the fabric that they use.
It might be worth a look at this site, she uses beautiful fabrics, and says that all her kilts are completely hand sewn Kates Kilts
Let you know of your progress