The coldest average temperature for Santo domingo, dominican republic is 75 degrees. Although rhinos in captivity have endured colder temps, ideally you will supplement with heat when temps fall below 70. I prefer kane pads in dry climates, but ceramic would be ok if your area has some humidity. Ceramics need to be sufficiently distanced to prevent thermal burns. With the pads there is the risk that if your iggys feel sick, they may not get off the pad and end up with a burn -- Most rhinos will lay next to a pad if it gets too hot for them. If you use the pads, use a thermostat and provide a large enough area so that the iggs can be laying well off the pad in the hide box.
Good luck.