Mick, Congrats! GR to NJ, back to GR, back to NJ, now there's a diaspora for you.
As regards the kilt, there is a company who makes Irish County tartan kilts - in fact, I wear my Co. Antrim tartan at a lot of festivals and shows.
You find your ancestral home county/counties and wear those tartans.
Make sure your kilt is wool. A cotton kilt an't gonna do you a damn bit of good in GR in March! Go get 'em big fella..
Seamus