Recommendation for external USB satellite tuner

I’m looking at putting together a media centre to watch / record satellite TV, play internet radio stations etc. I’m thinking of basing it on the Acer Revo N330 (dual core) as it’s small and low power so can be left on.

Any recommendations for an external usb satellite tuner that works well with Linux (particularly oS)? It’s only be for freeview (or free to air) unless external tuners with card slots exist.

I’ve checked the HCL but see only one option listed.