There are good VRBO condo style options in and around Turtle Bay for groups. Ko Olina has a few as well, but there are multiple hotels there so might be more what you are looking for. I've only done Aulani in Ko Olina, but many love the Marriott here.  Both are away from the masses. Things I like about each

1)Turtle Bay

-close to PCC and Temple

-good beaches

-quiet and less traffic than anywhere on the island

2)Ko Olina

-Beaches are amazing for small kids(no waves). 

-Close to Costco if you are making meals; Kihei has lots of dining options

-Doesn't rain much