Hi Weejam,
It's not really hard .... maybe a bit above child's play !
Here are some You Tube videos which will show you how to install a PCI-e graphics card:-
http://www.youtube.com/watch?v=b2M_UqO4cz4&feature=related
http://www.youtube.com/watch?v=TTFNXxHvn8w&feature=related
Most new computers will have the PCI- e (express) slot. However, a word of caution. Graphic cards are quite dependent on a good PSU (power supply unit). Would you know which one you have and what is the wattage ? A unit of 550 ~ 600 watts would be good.
Yes, Vstep products are rarely available off the shelf. I got SSE shipped from Holland to India and it cost me $67/- Well, it's a lot better than getting a Steam version (which is a little cheaper) as it is facing quite some problems.
Feel free to get back to me if you need any assistance.
Regards
vin_sun