the stock setup gives you a high gear you'll never need, a second high gear that will make no difference compared to coasting and two super low gears that I hope you'll never need. Admittedly I'm using my LHT primarily for around town riding and shopping with the lowest gears adequate for the kind of loads I would ever carry in a tour. I wanted a 172.5 crank so I went ahead and went to a compact double with 34/46 chainrings with a 1:1 low gear as my lowest. That said I rode it for 1/2 year with the stock triple and 13-27 cassette and loved it.
I'd be surprised if you really felt the need to change anything from stock if it's your first experience for long distance touring and wide range triple. 9spd cassettes give such a huge range of gears. If you had $120 to blow the 13-30 custom cassette from Harris Cyclery looks like a good idea. But I doubt that would have a practical benefit compared to using that money for other things like a rack or bags.