Sounds like you're headed for a sort of hybrid here. I'd suggest that you might acquaint yourself with some of the basic trad kilt construction techniques that might make the job easier.

Just how heavy is this wool? Remember that trad kilts are mostly made out of worsted which is heavy but still relatively "un-thick" and very flexible....a lot of coats are made out of a sort of "melton" type wool (like car coats and pea coats...not sure if melton is the correct word but it's as close as I can think of) and that's rather thick compared to worsted...doesn't have the same swing, either.

Best

AA