My husband and I had a wonderful time at Sandi’s place !
It is a bit far from the South of the island, but you mostly go there for the Waimea Canyon State Park, so it’s only one day of a bit more driving. Otherwise, location is great and the view on the mountains is just fabulous.
Equipment is provided for snorkelling and surfing.
Like previously mentioned in other comments, you definitely hear the circulation on the main road, but this isn’t a big issue, as it is not happening during night time.