I recently posted a similar question and a couple of users refered me to this link (http://www.linuxtv.org/wiki/index.php/DVB-S_Devices
I have been looking into this quite alot lately and there are several cards which appear to work ok. In particular i have been reading up on the WinTV-Nexus-S. (http://www.linuxtv.org/wiki/index.php/FF_Rev._2.2_DVB-S_Cards
) and it appears to be quite a common card that is used with VDR.
I also came across this one but it has very little linux support at this stage (there is alot of interest in it so it might change in the near future) - Hauppauge WintTV-HVR-4000. It has a quad tuner and (http://www.linuxtv.org/wiki/index.php/Hauppauge_WinTV-HVR-4000
Hope this helps