Caveat that they haven't been used for their intended purpose yet since DD1 hasn't started her period yet, but they're things we got in preparation.
KT by Knix has several period swimsuits We got DD1 this one. She says it's comfortable.
I also got her the sleepover short. I think I attached a picture of the "protection area" for that one. It's definitely heavier protected towards the back than the front. (I've always had the opposite problem than you were describing & leaked out the front since I'm a stomach/side sleeper, so the fact that there's so much more protection to the rear concerns me.)