Query about multi-monitor setup

[Devrij]

My gf has this SFF work tower and she wants to add a second monitor to it, but it only has the one vga output from the integrated gpu. There looks to be some small pci blanks on the back, presumably corresponding with pci ports (doubt they're pci-express). She's using her netbook to run a 2nd display for now, but it isn't ideal.

What's the easiest/cheapest way to hook up a 2nd monitor for her to work on as an extended desktop?

 

[Devrij]

I'd looked at these possibilities, and the 5450 would've been my first port of call, but I'm pretty sure it will be pci.

I'd looked at a usb display output, seeing as it's only for desktop work, but the thought makes me shudder. Presumably the cpu will take some of the workload on with a usb card as well, which this ancient little box could do without.