A graphics card that supports at least 6 monitors should be pretty easy to set up and manage through windows and the driver control panel
I have one that's used for multiple monitiors at multiple different resolutions and it's a breeze
If you go that rout, make sure there are enough ports ports to run your hdmi (or other display) cables through
Also, with six monitors you will inherently need enough outlets to plug into-if you have additional gear like a router/mainPC/printer, it could start to get pretty crowded running them all