I ended up getting a Speedo Xtra Life Ultraback, in plain black (my preference). The big pluses for me were the resistance to chlorine and the racer back. I ended up ordering through Amazon since it was cheaper there and DH has a trial of the prime account, so I got free shipping, too. It arrived tonight and fits perfectly!
Last night I went to water aerobics and my straps were falling down every few minutes. I can't wait to wear my new suit!
Thanks for all the replies - I will definitely check out some of these sites when I'm looking for a cuter (and hopefully smaller) suit for the summer.