I'm so glad to see you girls sharing information about Sunset Da Mona Lisa. It was difficult for me to find much info when we were planning our wedding. Feel free to e-mail me or post a Private Message for me, anytime you need info.
Our wedding had 40 people total and having the reception at the salon was adequately private enough. If you have the budget, renting out the place would be cool, otherwise, the salon should do it.
One piece of advice is to definitely try to get the salon, and not do the reception at the palapa. The palapa is NOT private at all, please don't let them convince you that it is. All regular restaurant patrons will have to walk right through your wedding reception in the palapa to get to the terraces.
Also, the advice I gave to Jessica regarding the construction is really important. We were promised verbally that the construction would stop during the wedding. Weird... we still heard jackhammering during the wedding... so put it in the contract!!