First off, unless cost is an issue, I really advise people to get a traditional woolen kilt made by an experienced kilt maker. You can get a 4-yard casual kilt now for between $300-$350 on average, which isn't that bad for an heirloom item that is going to outlast you if you treat it well.

So, my unsolicited advise over with, I'll be glad to give some reccomendations on tartans. If he does not want to wear the tartan of a particular clan or district, he might consider:

The Caledonia Tartan
The United States St. Andrew tartan (assuming he is American)
The Flower of Scotland
Jacobite
Scottish National
Pride of Scotland

These are just off the top of my head. There are more, and individual mills often have their own house tartans. Lochcarron has recently introduced a line of "Heirloom tartans" in a 13 oz weight in some very soft, nice colors, that include several general use designs.

I would also reccomend he think about getting a tweed kilt, or one of a solid color wool, as an alternative to tartan. These are just as nice, just as traditional, but often neglected. I'm wearing a nice blue tweek kilt as I write this and get compliments on it regularly.

Also, if he just wants a good kilt at a good price and doesn't care what tartan it is, he can keep a lookout for a second-hand kilt in his waist size. I once picked up an 80 year old MacGregor kilt, heavy wool, pleated to stripe, that I saw at auction. I have no ties to the clan whatsoever, but got it beacuse it was a beautiful heirloom item, it was just my size, and only $75.00. How could I resist!?

Aye,
Matt Newsome