Why are you trying to choose between programs that are for two completely different purposes? Your question is kind of like, “Should I use Windows or GTA5”.

Very nice and classy!

You can get much better deals on Ebay.

Here is one. But I don’t blame you for wanting to build your own. You could just start with an old desktop, throw some drives in it and install your choice of nas software. Might give you more money to buy more storage for your nas.

For that price you should just buy something from Synology

They have been having some nice deals on 2.5G unmanaged switches on Amazon for less than 90 bucks.

Not if you plan on installing any games.

Can you install something like TrueNas or OpenMediaVault on it?

Nice set up

Very nice!

Cosmo-server is much better and more secure that CasaOS. Check it out