Hi there and Welcome!!
I am the most indecisive person in the world so I have been trying to decide on a location in the Riviera Maya for about 2 months now!
There is tonnes of good info on this site. I would check out the threads in the Riviera Maya forum on why you chose the resort you did.
Having said that, a shortlist:
Riu Palace - looks lovely, but wedding coordinator can be slow, and there are not included/free wedding packages. there is a Riu next door to it that is more affordable for guests to stay at.
Moon Palace - gorgeous, more remote, well set up for easy wedding parties.
Dreams Tulum - supposed to be good for weddings, but a new resort with some construction still going on.
Grand Palladium Kanteneh or Colonial (next to each other and attached), are more affordable, but don't have good spaces for private parties.
There are lots more, but those are the ones that I have been gravitating towards.
Hope you enjoy this forum, beware, it's totally addictive! I've been away for 6 days and feel like i have missed out on everything!