I usually buy my bras and chones (that's undies to those not from the Southwest part of the country, or who don't speak Spanglish) from Victoria's Secret. I know they fit and it's what works...plus they're cute to boot!
The BRA: I was pleasantly surprised it was really comfy for a "going to work" or "t-shirt" bra. Not super sexy but looked great under clothes. It didn't ride up and didn't make me sweat or cut into my sides.
The PANTIES: These seemed like they were a little too small for my big butt. I'm pear shaped--well not really either, I just have an ass! Maybe a larger size would have worked better. I still wore them and they were pretty comfortable. I didn't like them as much as the bra, but still really nice for full butted underwear with no pantie lines.