You can hook these up through a regular kvm switch that allows you to use a single mouse, keyboard, monitor with more than one system. But you should read up a little before purchasing. Only certain switches will work correctly to switch servers using a keystroke combo. I have read that some didn't seem to work with a virtual keyboard like this tinykvm.

Yes, that's what a remote KVM switch (or, KVM-over-IP) does.

Here's a vendor with a lot of options: https://www.kvm-switches-online.com/kvm-switch-over-ip.html

Purchase a used enterprise KVM and some dongles. They are $10k+ new, but only hundreds used.