We scored a used Ketrike at a consignment store. That's a well-known brand and well-made, but pricey. You definitely want a handle and you definitely want it removable. So that if your child gets hooked a mom-powered ride, you can "lose" the handle in the garage. Also look for something that is adjustable so you get more years out of it. If the one you pick doesn't come with some sort of basket, be sure to get one. Even a cheap bicycle basket will be useful.