Ah yes, the “will it fit the mic holder” problem. Luckily, the microphone makers publish dimensions. I love my Sennheiser MKE600 which is 0.8 inches in diameter (20mm). So there you go.
But, in my experience, getting the mic close is more important than microphone quality, so the worst place for a microphone is on your camera. To record a voice, for instance, you need to get the shotgun within inches of the speaker’s mouth and that’s impossible if it is clamped in the mic holder.
And whatever your budget, make sure you set aside money for a boom pole, cables, and a dead cat. And of course a decent pair of headphones.
