iBoofKratom

Logitech or Corsair keyboards are always good. 

Well, I thought you would actually. Then you'd use the microwave PC as your own rig
 
So the Microwave Rig is the 2600X / RX580?

avoid the thermaltake SMART series, and don't buy thermal paste since the CPU cooler comes with some already. Perhaps downsize the SSD and throw some money towards a motherboard with a proper VRM heat sink.
https://pcpartpicker.com/product/kRTzK8/msi-b450m-pro-vdh-max-micro-atx-am4-motherboard-b450m-pro-vdh-max
or buy it from newegg where it's basically the same price as that mobo.

So where is the 9900K?

As with any good microwave build you gotta make your own and make it work! 

Then buy better fans, or look into water cooling

Dude that could mean a 6 core 980x, a 4 core 2600k, or an 8 core 9700kf, maybe even a 10-core 6950x we need more

I know what you’ve always wanted, to cook your nuggies next to the rig. 

He talked about this in an honest answers video. My advice to you is you don't need him to start your channel. You can build a PC yourself. He has millions of fans so he can't just help you because then everyone would start asking.

Let's be honest, who should you believe... The manufacturer or random people?
Here is the CPU support list from REV 3.1 which shows it supports certain AM3+ CPU's:
https://www.gigabyte.com/Motherboard/GA-880GA-UD3H-rev-31/support#support-cpu
 
Whether you should get an AM3+ CPU in this day and age is another conversation though.

just saying if you ever want to upgrade

if the gaming plus is too expensive, go for the ds3h, knowing that you're limited to 6 core cpus, as it can't really handle an 8 core

You can buy a pci-e riser and place it in that area under the motherboard.
Rosewill RCRC-18001 Mining Card, Riser Card, PCIe (PCI Express) 16x to 1x Riser Adapter, USB 3.0 Extension Cable 60cm, 6 pin PCI-E to SATA Power Cable, GPU Riser Adapter, Ethereum Mining Riser Card - Newegg.com
Rosewill RCRC-17001 Mining Card, Riser Card, PCIe (PCI Express) 16x to 1x Riser Adapter, USB 3.0 Extension Cable 60cm, 6 pin PCI-E to SATA Power Cable, GPU Riser Adapter, Ethereum Mining Riser Card - Newegg.com
 
Small card goes into the pci-e x1 slot, and you use a regular usb 3 cable between the small card and the big card. The usb 3 cable connects only the signal wires from the pci-e x1 slot so you need to power the slot separately through that 6 pin connector.  It's a pci-e 6pin connector, but they'll bundle either a pci-e 6pin -> sata or pci-e 6pin / molex adapter with this.
The back is insulated with some rubber material , some even have double sided adhesive, so you can just put them below the board and you can screw your pci-e x1 card to the case.
 
eBay and Amazon and newegg is full of such cards, some will have straight sata or molex header on board so you don't need to use adapter cables (provided with the adapter)

 
 
example of similar boards :
Amazon.com: EXPLOMOS Latest PCI-E Express Cable 1X to 16X Graphics Extension Ethereum ETH Mining Powered Riser Adapter Card, 60cm Blue USB 3.0 Cable, 4 Solid Capacitors (VER 008S, 1-Pack): Computers & Accessories
 

 

I know what you’ve always wanted, to cook your nuggies next to the rig. 

I know what you’ve always wanted, to cook your nuggies next to the rig. 

Melt the temps away

This is the cheapest B450 motherboard I would recommend: ASRock B450M PRO4 Micro ATX. 

Get the 2600 it’s a fair price for the bang. 

From this list I'll get the b450 tomahawk max with a 2600x or 3600...

because 
and you want it

Ryzen 2600X won’t stear ya wrong

This is great advice 
 

Normally the base-t standards are rated for 100m, so you will be fine. 
 
For ethernet, speed runs at one of the given link speeds(like 10gbe, 1gbe, 100m), and unless you have errors or dropouts, it will run at that speed.

Which is basically 1.2V anyways