The Irish National is a great looking tartan (IMHO, of course). We're about the same size so I'd recommend a Stillwater standard 40". Then I'd recommend a black sporran (Thorfinns are grand, but a Stillwater Nylon Cargo Sporran will do), a black belt (40" long, 2 1/2" wide) and a matching 44" leather sporran belt (both from Oconee Leather works) for essential accessories.

Kilt on, and good luck!