Traction is important in caving boots for grip in deep mud or slippery cave passages. Many cavers wear hiking boots that provide strong ankle support to prevent sprains and twists. If your feet still tend to get cold, try wearing polypropolyne liners under your wool socks. Scuba socks work well at keeping you feet dry and warm in wet caves. Wear polypropolyne and other synthetics.
Coveralls are nice at keeping bottom layers dry as well as providing an extra layer of clothing.
Coveralls with Velcro are preferred to zippers because zippers can get clogged with mud. Gloves are important for protecting your hands, especially if you are doing a lot of crawling and climbing. Biking gloves work well if you like to have your fingers free. Scuba gloves work if you cave in cold water, but remember, it's hard to take the gloves off and on. Kneepads are definitely a must.