What bathing suit should I buy?

Okay so I'm going to the beach this weekend with my church and I need a bathing suit, I'm a tad lopsided if you know what I mean, and a but larger than most 14 year-olds. I really need coverage, but still in a bikini. Ive tried the triangular halter top ones, but they just don't cover enough. What basic type has coverage and minimizes lopsidedness?