Hello and welcome to the forum. Riveria Maya and cabo are both great locations, tough decision. :-) I think Cabo might be a little more expensive to fly to, so if you or your family/friends are on a budget, you might want to look into Riveria Maya. However with that said, I was married in Cabo and it was great.
We have so many threads on both locations with many different resorts for both, I'm sure if you just start digging up those threads you'll start to narrow down the location/resort. Best of luck and happy planning