Hello and Welcome to the forum. First love seeing other Mi brides on here. :-)
If your looking at going to the ruins, then you need to stay in the Cancun, Rivera Maya, Tulum or Playa Del Carmen area. Those locations have all those options that you are looking for, nice beaches, ceremony on the beach, etc. Plus it's usually a fast trip from MI, I think like just over 3 hours, so that of course would save you money on travel expenses as well.
Happy planning and again welcome to the forum.