I sent a PM and if you give me your email address I can send everything that I have which will list all the reception locations for private and semi-private dinners. The private areas are Baja Norte, English Garden, a beach area, La Plaza Bar and ballroom.
Semi-private dinners can be held at San Jose and Mar de Cortes, but they can hold private events.
For external vendors they charge $300 USD per day fee.
We are having our ceremony at the gazebo, but I believe you can rent another one if your prefer something different. The Riu's floral vendor is Baja Flowers and their website is www.bajaflower.com. The contact is Alina Gomez at firstname.lastname@example.org. I have had initial contact with her and she is very helpful as she sent a general price list, the flowers they have in season and pictures.