What kind of headset mike for my KS Rack vocoder?

Hi guys. I want to start using the vocoder feature in my KS rack. If at all possible, I want to plug the mike directly into the audio input. It has a setting for microphone sensitivity (as opposed to line), so I assume I won't need a preamp. Which is good - the fewer parts the better.

But I don't know much about microphones. I understand there are two basic types: electret and dynamic. Does it make a difference for this purpose?

Also, I'd love a headset mike, which would have to work with my existing headphones. And because it's a vocoder, the quality of the mike is not super important.

Can anyone give me advice? KS-rack audio in: electret or dynamic mike? Recommendation for a cheapish headset mike that I can wear with my headphones?

Thanks.

-Ron.