Update on the bandeau search: J Crew is having a great sale online, so I ordered a bunch of swimsuits. It was a big challenge to find a swimsuit that didn't have a too much padding, but just enough lining and such for support. So, ladies w/ are an a-cup (I ordered x-small), here are a couple of good options:
Women's catalog/jcrew.com exclusives - swim - Solid ruffle bandeau top - J.Crew
Women's Swimwear - Bikinis, Separates & Tops, Tank Suits & Novelty Swimwear - J.Crew
Not a fan of this one. The fabric needed lining (too thin).
Women's Beachwear - Swimwear, Swimsuits, Tees, Flip Flops, Cover-Ups & Accessories - J.Crew
Hope this helps someone!