Open questions:

Does the NR200 come with fans already?

I think 3 fans are already included with it? (Top: 2 x 120mm fan (1 x 120mm fan Pre-installed); Rear: 1 x 92mm fan (Pre-installed))

Yes. But you only get two fans. 1x 120mm and 1x 92mm. The NR200(P) comes with 2x 120mm.

Thoughts on a good mini-itx motherboard?

This is fine for what you need it to do

I do have a microcenter nearby as an option as well. Maybe could also find NR200+psu combination sales, though I kind of wanted ATX to save cost. If there is a cheap SFX option I'm open to that, but I think most I've seen are all $100+.

I would never gamble on a cheap power supply. But then again. I've also set power supplies on fire. Not on purpose. It's pretty scary. If you can set a power supply on fire doing nothing, then the power supply could easily catch on fire just idling... like in the middle of the night when people are sleeping.

If I may offer you an alternative: This is a Chopin case. It comes with a power supply. Combined, it is cheaper than buying the NR200 plus an additional power supply. You still get to build a machine, they get a computer.

Or you can buy a NUC or AMD MiniPC for that price tag very easily. No setup necessary, and they're small. So small that you can 3M tape it to the back of a monitor or TV. The hardware is good enough for basic browsing, facebook, youtube, word processing.

Edit! I see you're a PM. Do I need to write a business case?

Usually they are big cases. However there are some small cases like the inwin chopin that could fit your needs. I'll try to fit a build for around 500$ with the 5600G in a second