Dual Monitor Setup?

As long as he has a graphics card with multiple ports, he is good to go.

It's really not taxing unless he plans on doing some dual screen gaming :)

I didn't dream about having 2 monitors, until I upgraded my GPU and I saw....2 dvi ports, hmm, what could happen If I plug in another monitor, and.....TADAAAM now I have 2 monitors, multi-display, so, a larger display. I kinda really fucking love it even if the 2 monitors don't have nothing in common nope, they are not the same mondel, size, etc. Once you go 2+ monitors, you will never go back.

Depending on your GPU, you will need to get a mini or normal DisplayPort Cable for the second monitor.
I wouldn't reccomend trying the HDMI port, because a lot of important info of that second monitor is lost that way and it might only be recognised as a 720p Monitor or TV.

My GPU pretty much looks like that one in the picture and I am using a 144hz and 60hz monitor in "expanded mode" and everything works fine. :)

he feels that he could get work done faster and more efficiently.

He is right about that. Also about the setup etc. all you need is two monitor ports(don't have to be the same type of ports) on the graphics card as @AtomicWoodchuck said.

If your dad wants, he could get a 21:9 ultra widescreen monitor and use the "Split screen" feature to have everything side by side. Though, at the moment the cheapest good 21:9 monitor is the LG 25" (they go up to 34" I believe) is ~$249 USD. :/

All you need to do is connect the monitors to the ports and select as individual displays or extended and you're done. :)

other commenters got it first, but once you go multiple monitors, you can never go back. been running 3 monitors for a while now and went to visit my brother and used his 1 monitor pc and it was awful heh.

I've got 2 monitors at work and i love it.

Thanks for all the replies guys. This really helps.