I have Sphodromantis viridis. He bites sometimes, but seems hardy and easy to feed. I also have two Creobroter pictipennis. They are a little skittish, but don't mind being handled. They do jump, though, so you have to be careful. I heard Phyllocrania paradoxa (ghost mantids) are good beginner mantids, and also shield mantids. Shields are a little more expensive, but get big, and live a little longer than the average year.