I have stayed in a few awesome places:

* Blue Lagoon Beach Resort in the Yasawas
* Nanuya Island Resort (more for couples)
* Toberua Island Resort (you need to go to Suva after you arrive in Fiji, then Suva to the Island.

Usually because of the timings of flights and transfers, you have to stay overnight in Nadi and get the transfer to your island in the morning. There is no need to spend much money, its just overnight for a bed! The Raffles Gateway is a great place for a family if you have to transfer. You may also have this issue coming home.

You can fly immediately via seaplane, but its exxy. Only 30 mins to the Yasawas when you're ready to fly (beautiful scenery though!), otherwise 4 hours on the Yasawa Flyer (opt for the captains lounge upgrade so you get aircon, snacks etc).

I LOVE the Yasawas though, would definitely pay the extra to go there.