I just got the latest TravelSmith catalog. I love their stuff ... it's designed for travelers so many of their clothes are wrinkle and stain resistant. Men & Women's wear, free catalog. I'd say about 40% of their clothes are available up to 3X. Price wise ~ moderately expensive.

JC Penney offers about half it's clothes to size 3X. My mom likes this place and thinks it carries quality clothes ... but I'm not such a big fan. Moderate prices and free catalog.

Also ~ a bit off topic but Ample Stuff carries 'everything for big people but clothes'. Scales that weigh up to 1,000 pounds, large size exam gowns, XL umbrellas, wide width socks, etc.

Decent Exposures makes comfortable bras up to 54L! It's a small, women own business that has been operating in Seattle for many years. I had a bra made for me out of plush maroon velour ... so comfortable I forgot I was wearing it. They're not all that supportive, but good for containment and jiggle control. Price $30-$50 each.

Regarding Lane Bryant's attitude about using fat models: Ditto.