Probably too late, but we just did that tour last week with Yhoni (not the correct spelling I'm sure) with cave-tubing.com. No up front deposit, and we paid AFTER the excursion was over. We had a blast! Reggie was actually our first choice, but my dad got a senior's discount with Yhoni which amounted to $25.00 for his cave tubing experience. Both I've seen recommended many times, so whichever way you go, you'll be fine.