They also make a SPF 50 hat- however it has nylon in it, and I find when it gets wet, it flops in children's faces. It retails for approx $25, which some people might find high, however that breaks down to $4.16 per year. I can attest it last that long, and is durable.
Also I am not a huge fan of the giant flower that they put on the girls hats. However it is removable, though it costs more money for the girls hats(due to huge flower).
I prefer 2 piece bathing suits for my children due to the many bathroom breaks. My daughter wears a bottom that doesn't let her cheeks fall out and a Stella sun guard top, and my son wears surfer shorts and a slater sun guard top. This also leaves less skin area that needs to be lathered up with sunscreen. You can purchase from their store on colonade road (warehouse) or on-line: http://www.levelsix.com/store/index.php/you/kids/slater-short-sleeve-sun-guard.html