I will personally recommend The combination tour I did with my family with a private operator in Belize. We did a combination of both the ruins of Altun Ha and the Baboon Sanctuary. We had a great time. our tour guide was Donald and ha took good care of us and gave us a nice time as well. He loves his people and love his job. He is very professional.***edited to remove commercial reference***
You will love the jungle. We searched for Howler Monkeys in the jungle too. The were no mosquitos. You will love it. Give it a try.