Do you want Gordon modern regular?
Gordon ancient/faded?
Dress Gordon?
Red Gordon?

There are a few choices. Gordon is one of the most common tartans, and also worn by a famous Highland regiment (at least historically, I'm not sure what is happening right now-> they are doing strange things-> I'm sure CanjunScot and others could enlighten us quickly).

A decent Gordon modern is the PV carried by USA Kilts (made by Marton Mills). Rocky or another kilt maker may be able to get you some. Also both The Scottish Tartan Museum in Franklin, NC (an X Marks sponsor) and The Scottish Weaver (who carries -stock- a light weight plain weave that might make a decent skirt-> NOT and X Marks sponsor) can get some worsted wool from numerous mils and in numerous weights.