I just got married at Mahekal a couple weeks ago and am so glad to see other people considering it. It sounds like the exact type of place you are looking for (did you like what you saw there?) I just loved how relaxed and low-key it was - I grew up going there with family and then my fiance and I stayed there last year (he proposed in Tulum) so it holds a lot of meaning for us. Our wedding was approximately 80 people. The service was fantastic for a group of that size and the wedding coordinator will really accommodate anything you need. Two out of three meals were included per day for guests, which is standard there.
We actually held a post-wedding beach party/lunch the following day. My fiance and I had one of the cabanas right on the beach with a larger porch, so they put all the food out and they let us provide our own drinks (that is probably unheard of at the biggie resorts) AND the concierge went to Walmart himself to buy a volleyball net for us to use! You get a level of personalized service at Mahekal that is just phenomenal. They really get to know you and you almost feel like you're part of the Mahekal family when you plan an event there. Plus it just has that chilled out, relaxed vibe - which is exactly what suited our needs. We didn't need or want anything super flashy or blingy and our guests really, really enjoyed themselves and felt right at home there.
That's my two cents - if you liked what you saw, definitely check with Ayahamint Aguirre, their wedding coordinator for info. Her email is email@example.com. I think you won't be disappointed.
Congrats and enjoy - as stressful as it was to plan a wedding in another country -I wouldn't change the experience for the world!!