OP .... I think your best to go there and have a look around to see which resort & beach suits.
As there's so many of them to choose from. Most of the beaches are quite nice, but it depends do you want peace and no tourists nearby or you want to be near the supermarket ... or bar or whatever.
Ao Prao is a bit pricey as it's more upmarket than others on the island.
Also, we stayed at Wongduan resort a few times, it's right on the beach as most are.
As I said, if you can go and have a look then fine ....
get the boat over, then the pickup ... get off at the beach and then walk along ...2..3 klms and see what you like, I think Wongduen was further along so you would need the pickup ride again. Malibu was about half way.