You don't want to get an anemone until your tank is over a year old. By then, with a year's experience, you may understand the difficulty in keeping such an animal in a captive environment. Survival rates are dismally low. A large hairy mushroom, frogspawn coral, or other soft coral can host a clown fish and provide a good substitute for the symbiotic relationship between a clown and anemone without killing an anemone.
If after a year (when your tank is matured) and you want to have an anemone tank get a tank raised bubble tip. They are a little harder to find but are the best choice. Anemones are not really reef dwellers though, that's why they should be kept in a species tank. They are often found in the sand away from the coral reef structure.