I've went there a few years ago, its beautiful! If you do end up going there, there is a lagoon on the dutch side of the island that has the best beach. Very little waves, water is very clear. I dont remember exactly where it is though
I came back from Tahiti a few weeks ago. No other island vacation matched this one. Absolutely gorgeous. No words to describe it, its better then paradise. Similar to Hawaii, but less commercial, more remote. Its definately pricey but it was worth every single penny. I not sure about wedding there though, I think you could have a ceremony there but I dont think it would be a legally binding.
We have gone twice. Beautiful island. We stayed the first time on the French side and the second time on the Dutch side. I prefer staying on the Dutch side but enjoyed the shopping and eating on the French side. We rented a car both times so could get around to either side of the island. I recommend you do that. Too many pretty beaches not to see them all.