I have been fit-boxing for almost 2 and half years, and I use both. I put on straps underneath to protect my wrist, then a pair of well padded glove shown
here. Though I am a girl of a smaller frame (165cm/54kg) and never a real boxer, I quickly gained strength for delivery and I couldn't do without either.
Even if your goal is mainly aerobic accomplishment, once you learn proper forms and delivery technique, your knuckles and wrists will take quite a beating, especially considering that you have been already well trained and conditioned, and it is wise to protect them properly.
It is really a fun exercise and I love it... hope you will, too!!