I can not speak to the lag without testing it but a lot of the time these old PCI cards are pretty low latency. It is almost certain to be hugely better than any cheap and nasty USB things you might have seen.
If you do happen to need a driver (the page makes it sound like something might be needed) then
http://www.pctvsystems.com/Support/Downloads/Driver/tabid/123/language/en-GB/Default.aspx should have them, it says Vista but you should be able to force it through on later operating systems.
For most capture purposes I suggest virtualdub, it is far better than the bundled junk that comes with the average TV card and certainly better than whatever stock windows can cook up. Click the file dropdown menu and then "capture AVI" to get to the capture mode.
http://www.virtualdub.org/docs_capture.html
If you are just wanting to play the games and not capture any footage then ignore the next few lines.
The only downside to virtualdub is it will want VFW codecs rather than the standalone or directshow versions. Fortunately people backported many things to it
http://sourceforge.net/projects/x264vfw/ for X264/H264
http://sourceforge.net/projects/ffdshow-tryout/ has several more.
Personally I suggest capturing to a lossless codec, ffdshow above probably has it inbuilt but huffyuv is what I tend to use (
http://www.videohelp.com/software/HuffYUV ).
If you are just playing then I still suggest virtualdub, you can usually get most of the GUI out of the way if it bother you, although I would suggest keeping it slightly windowed as 576i/480i, or worse, does not look great when upscaled in real time to 1080p or whatever your computer screen is at.