This motherboard is cheaper, and is a slightly better fit for that case.
It has 2 PCIe expansion!
If you need the power of the i3-8100, get that… but for simple NAS use the G4900T is about 1/3 the price when using the “best offer” feature. It can still handle a ton of transcodes. It’s slower if you’re doing unpacking and whatnot, but you could limit those things to a single core to reduce their impact.