XTreme Adventure Cancun offers super fun tours with great guides. They're particularly recommended for activities like Isla Mujeres, which is a MUST.
3 recommendations in Services
Recommendations in Cancún
Consider Akah Photography for your engagement photoshoot in Cancun. They offer reasonable prices comparable to the on-site hotel package. Since it's a short notice, you may want to reach out to them directly to discuss your budget and see what options might make sense.