If the actors don't have to actually put the kilt on while on stage, the quick, cheap answer might be to get some plaid material and do a belted great kilt or "little kilt" number:

http://www.theweebsite.com/greatkilt/index.html

...having a hard time finding a pictorial of doing the "little kilt", but it's the same kind of thing...laying it out flat with pleats in the middle and a front and rear apron and holding the whole thing together with a belt.

Best

AA