For a great kilt it doesn't matter so much where it comes from since it's basically just a big piece of cloth.

You'll want about 5 yards, and the edges should be frayed out. A really good idea is to have belt loops sewn in to facilitate donning the beast. (My doesn't have said loops although William MacIntosh himself tried to tell me better when I ordered it.)

Good luck. And send pix!

P.X. You can just buy a piece of double width tartan and fray the edges yourself.