Lands End suits fit pretty well in my experience, so that would usually be my first recommendation. But, they have a very limited selection of colors right now as it's past swimsuit season:
http://www.landsend.com/pp/BeachLivi...n&origin=index
You could also check a site like Speedo or TYR, as those suits (even their 2-piece ones) are generally made more for performance than for fashion, meaning you'll likely get better coverage.
Sorry I'm not more help on the bikini bottom front - it's not something I normally shop for!
When you ARE in the market for a one-piece, I would highly recommend this suit from Lands End:
http://www.landsend.com/pp/AlloverCo...n&origin=index. It's not cheap, but it has an underwire bra and is very supportive. I have a DDD cup size, but given that the DDD cup has been too big for me when I have ordered this suit in the past (a D is much better on me in this suit, and I can even do the regular), I am guessing that the DDD might work for you. The shape is also flattering and the suit is high-quality, and I think it would hold up well even with being in the pool multiple times per week. The good thing about Lands End as well is that returns can be made to a Sears store (that retails Lands End) at anytime... meaning that if you ordered it but only had a chance to return it months later, or have your parents return it after a visit, that would be fine.