Have a read through the forum, especially the linux receivers section, as this seems to be the best option, at the moment, read the sticky threads and guides.
Cams, and cards, seem to be a waste of money, at the moment, the cost, for what they open, and the lack of support.
You can also talk to the forum sponsors, like Southern Satellite, they will advise you on which product might best suit your needs, depending on your needs and expertise.