I know plenty of Vegan kilt-wearers. It's not so incongruous.
Welcome to Xmarks!

I'd recommend having a wee go at making your own accessories from any kind of sturdy fke leather you can find. I've seen a few folk do it and they've even managed to make lovely, full-dress sporrans.

Also, I think there MAY be a Heathen and Pagan group which focuses on Scottish Ancestry in the state of New York. You can probably find them on Witchvox.
If I ever find where I saw them again I will be sure to PM you with it.