Another Texan here. We did the jungle thing and stayed at a place called duPlooy's. It wasn't to far from San Ignacio, and they had drivers that would take you there to shop or have dinner etc. DuPlooy's has tours that they will set up and book for you. If you're a guest, they take care of all the details. A guide, a sack lunch if you need one, transportation, etc. A top notch facility and super nice people. They had several cave tours on their list of things to do. The prices seemed reasonable to me as well. The food there is to die for. The lodgings were fantastic, and if you like plants etc. the botanical gardens on the grounds were outstanding. The resort sits right on the Macal River, so you can take a canoe from there to San Ignacio any time you want. They will pick you up. The swimming in the river was "other worldly" and a very peaceful experience. I suggest looking it up on the net. They have quite a bit of information.
Debbie on the Texas Coast