What I use in my own stream:
Focusrite Scarlett 8i6 3rd Gen USB Audio Interface
This is the input I use for my audio. It inputs my microphone, and I have a lot of options for putting additional audio sources into it if I want. there are also 2 headphone ports. You do not have to get this level of interface, there are others made by Focusrite that may be enough for you without being as expensive.
ProFormance P725 Supercardioid Dynamic Handheld Microphone
I use this to capture my voice during streams. It super focuses on my voice and very little outside of it. With a good microphone like this you should not need all the noise filters, noise gates, and other things that can make you sound unnatural.
Razer Huntsman Mini
I just picked this up recently for playing keyboard and mouse games. It is awesome to have so much room between the mouse and the keyboard (Because this thing is so much smaller than your average keyboard). If you are looking to save room and want to have as much room for your mouse as possible, this is a good choice!
Razer Ornata Chroma Gaming Keyboard
Ok, so this is the keyboard I have connected to my desktop for generic typing stuff. I was walking through a store about 5 years ago and happened to touch a couple of the keys and instantly decided I needed it in my life! I LOVE THE FEEL OF THE KEYS! Anyhow, I think you may love it as much as I do.
Cooler Master MasterCase H500
This is the case on my streaming/gaming computer, and let me tell you it never ever gets warm! The two gi-normous fans on the front of the case at 50% power (cannot really hear them) are basically the only fans you would really need, but there are places for more fans too!