last i checked, they had a couple of different flavors of seitan-based stuff (teriyaki and Thai peanut, i think). the soy ones have a different texture but are also pretty good. i haven't tried the mushroom-based variant.

i know the Harvest Coop in Central used to sell this stuff, and out in LA Whole Foods has a decent selection, so you might want to try a Boston-area Whole Foods.

η: also, you can order them from amazon, although only in large quantities (and without any really competitive bulk pricing, alas).