tvheadend supports all the DVB cards that are working/supported under Linux. The best place to look for information about which cards are supported is linuxtv.org.
Most cards have their own page on the linuxtv.org wiki. Here is the link to your card:
http://linuxtv.org/wiki/index.php/Leadtek_WinFast_DTV1000_S
And on that page it says:
> It is currently not supported, although all individual component parts are all supported. Work in progress!
but further down it says:
> This card can now work by following: http://tw1965.myweb.hinet.net/
But that site is exterly slow when I tried it just now, I could get something from the google cache, but it was not clear to me what to do to make this card work.
Using Google I also found this thread with some more information
http://forums.whirlpool.net.au/archive/942269
It might be difficult to make it work, and then you are not sure if it will keep on working with newer kernels etc etc. You might be better off using a different card if you are not the kind of person that likes to experiment to get things working.
Hein