and his grandmother has agreed to make one.

Knowing that this kid will outgrow this kilt in something under twenty seconds, I'm looking for recommendations for fabric that will survive serious farm-kid wear. I doubt that a particular tartan is required, just a sturdy plaid fabric. Also, we have a sporran issue: I can't see a full adult-sized sporran working for a six year-old.

Any sources you care to suggest will be forwarded to this grandmother, who deserves plaudits for her willingness to make a kilt for her grandson.