a small x86 box with a couple nics and opnsense would work far better.

I go thru the floor but my house is made of wood and drywall.

you need to install samba and setup a share on the linux box first.

this is more suited for r/linux4noobs.

Too old and power hungry at this point. Plus the raid controllers of that generation only support up to 2tb.

Aim for at least a T320 or R320.

Nah, the virtual kvm in the remote management on them doesn’t work anymore. Go for a Rx20 series or newer. Those have a html5 based kvm.