I'm getting married at The Royal June 10, 2011. I used destinationweddings.com to coordinate all my travel, and although we probably could have did it ourselves, we got a lot of additional benefits... Free dinner on the beach (which is $250), plus our TA is very helpful whenever we have questions about Mexico, tours/excursions, and she has resolved many communication errors between myself and the resort.
We made our reservations about 8.5 months in advance, which was as soon as the air prices were released. And were staying in the Presidential Suite and doing the free wedding package. We're adding on what we want because it'll only be the two of us anyway. I advise you to do your research on their website, mostly everything you need to know is there.
If you plan to use any outside vendors, they do have a $350 vendor fee, and apparently now that is per day, but when I made my reservations it was per vendor. (Our photographer will be there two days, one for the wedding and for the TTD the next day.)
IDK, if you have any other questions you can message me!
Good luck & congrats!