If you really want a chameleon and you do not have the proper space to care for one you should sell off the veiled and buy some pygmy chameleons. The setup your talking about with a tank and topper would great for a pygmy if you don't get too cold in your area. If it does get cold, forget the topper and get a hood and your pygmies will be happy.
A veiled should never be kept in the type of tank you are talking about. In the UK they do use glass but they use tall well ventilated tank that are designed to hold in warmth for their colder climate and are designed for chameleons.