Hello Andrew,
I am using Technotrend 1500-S cards. A budget DVB-S card working out of the box for Debian 4.0 (with kernel 2.6.18-5), so should not cause any kind of a problem. Another one I recently acquired is a Technotrend 1500-C card. Unfortunately, I can't test it at the moment, due to lack of cable in my house.
I have another DVB-S card, which I can't get to work at all. It is a TechniSat SkyStar 2 TV, a budget card DVB-S. The name is misleading, as it uses a different design, than previous SkyStar 2s :-(. It seems the SkyStar 2 with a metal box are working, the once without a metal box are not supported under Linux at the moment. At least according to the DVB wiki.
Hope this information helps.
rgds
Oliver