It will be my daily computer for browsing, documents and occasional photo editing.

On Linux, that does really not need much computing power or RAM nowadays. I use a thinkpad T490 with 8 GB RAM with Debian and Gnome / i3 on it. Runs like a charm. A friend of mine is working happily with a Thinkpad X220.

I use a 400 as a NAS. Nice thing, it has a keyboard and can be shut down cleanly.

And a Rasberry Pi B is good enough as a light web server and can be powered via USB from a FritzBox, thus cheap in power.