Your children would be able to ride everything (including water rides and other non-coaster rides) except for Kumba, Sheikra, and Montu. Rumor has it that when Cheetah Hunt opens, the height requirement will be 48", but that is still to be determined. We spent four consecutive days at BGT, so obviously we loved the park. There is so much to do, see, and experience that riding the coasters took very little time during our four day visit. We loved exploring the animal habitats and meeting the zookeepers. They have various times throughout the day when the zookeepers make appearances to talk with visitors and interact with the animals. It was fascinating. The shows were fantastic, and we saw them each two or three times. Jungle Fantasy, Burn the Floor, and Sweet Music are awesome stage productions, and Critter Castaways is the best animal show I've ever seen anywhere. The food is fabulous, and the park is huge. I can't recommend it enough. As far as combining it with a visit to Universal...I've never visited Universal, but I like BGT's link to nature and the outdoors, so I think it would be a relaxing contrast.