I personally am a pre Culloden reenactor. There was a ban on highland dress ennacted in the mid 17th century. Highland dress didn't really enjoy a resurgence in anything other than regimental form until the 1900's. Also, most of the original tartan designs were lost because they were made by oral tradition and apprenticeship. The ban killed off the last generation of "authentic" tartan weavers with no real record of thread counts, setts, etc, being left. So if you're an 18th century military reenactor, the little kilt is most accurate. If you're a civilian, it's trousers, for the most part. Mat Newsome at http://kiltmaker.blogspot.com/ has some excellent information regarding Highland dress. You may be able to get some more details there.