I'm newly engaged

and FI and I are considering a Hawaii wedding - more than likely just us and our three kids. We're thinking a short ceremony on the beach, followed by lunch/dinner somewhere. With the exception of adding in our kids, it's really more of an elopement.
FI's thinking Kauai because it's new to both of us, and we've heard it's just as pretty as Maui but maybe more secluded. I'm maybe leaning towards Maui just a bit, but that's only because I've been there before (once) and feel it would be easy to plan...but Kauai seems awesome too!
All told, we plan on spending about 10 days in Hawaii. A possible compromise I thought of would be to fly to Maui and get married there, but then go to Kauai mid-trip. I think I had heard once that the seas around Kauai are rougher than Maui. Is this the case? Our favorite activity is snorkeling, but one of our kids is still small and wouldn't do well in strong currents.
Does anyone have any suggestions or recommendations? Things to consider? Ideas? Thanks!