Tony - in your first post ou mention two different cards, and with the single output 1300 with the splitter cable, I pressume it's card software and features that allow desktop on one screen and anything else on the other. I doubt my built in mobo head gfx will support this - so a VGA splitter cable from my single output will probably only result in two screens showing the same thing...
As for a freeview card for the PC, I deliberately went the route I have with a standalone box cos I want it to be independant of the PC.