Which 2 Hawaiian Islands to visit? My honeymoon is exactly 1 year from today.?

I will be 25 and my fiance' will be 32, we very much want to relax but still enjoy a party night. We want to spend 11 days and 11 nights split on two islands. We are looking for seclusion more toward the start of the trip, but beauty always, some night life when we choose, but do not want anything too touristy. We are not too big on history or extreme botanical sights (more like all around basic beauty but don't want to focus all day on it). Musts though are horseback riding on the beach, a helicopter ride, snorkeling, would like to see some dolphins, wind surfing, fishing, see a volcano, swim by a waterfall, and go to a luau. And at least on one of the islands we would like to stay in an ocean front room (most likely during the seclusion time). We are arriving the 25th of June and leaving the 6th of July, we will be on an island for 4th of July! Any suggestions on which two islands to go to? And how many days at either would you suggest being there?