What do I need for a talk box?
You'll only need a microphone if you're trying to record yourself, or perform live. A talkbox actually IS a speaker, so you can plug your synth into it and play. The sound essentially comes out of your mouth through the tube, and you just move your mouth to use it.
Do you need an amp for a talk box?
You use your mouth to 'shape' the sound, and a microphone takes that sound to the PA system. So, you need: - An amp to drive the talkbox speaker.