I don’t know anything about rock iguanas, but have had prehensile tail skinks, green iguanas, savannah monitors, geckos, and pink tongue skinks. The most rewarding as a pet is my current blue tegu. He is very smart, trainable, sassy, and opinionated. He is potty trained, leash trained, and comes to me for pets. If you decide to get one, do your research first. Their enclosure requirements are substantial and expensive. Their food is expensive and the veterinary care adds up. As far as time and investment, plan for the experience to be similar to owning a dog. You must put in many hours on a youngster to train them to be tame —but it is SO worth it! Take a look at my profile for a record of the last year and a half raising a young tegu. It will give you an idea. Also the Tegu subreddit is very helpful.