A few scenario's for a cable card/tv tuners?

Get a Hauppauge HD-PVR. You can feed the component video output from your cable box to the HD-PVR and connect it to your PC via a USB cable. I'm not sure which audio interfaces are used on the HD-PVR bit they will probably work with whatever cable box you are using.

An ATI DCT is usually cheaper than a HD PVR and will save you STB rental fee every month. The Ceton InfinTV at $400 is actaully cheaper per tuner since it has 4 and also only requires 1 cablecard (ATI DCT and HD PVR+STB require a cablecard per each unit).

Any ATSC tuner should work as for antenna it all depends on your location, check antennaweb.org to see what type of antenna you'd should need and what channels you'd should get.

The ATI DCT is a single tuner and no longer works on a lot of systems, especially FIOS, and will still require renting a CableCard to use it. The Ceton card is the best current solution if you want to eliminate the cable box and the SiliconDust HDHomeRun Prime is set to be released into the wild in the near future. The HD PVR is available now and the new Colossus version is coming soon (it may already be out but I'm not entirely sure). Ordering any of the other CableCard tuners will require being on a waiting list.

The ATI DCT should only have problems w/ the hand full of FiOS markets that have changed to the multicrypt however eventually they will get all their markets done, it's possible that someone could make the needed firmware update (the current one was developed more by outside sources than from ATI) but the current owners (no longer ATI) aren't doing anything to support it. I think all the other providers only use 1 type of encryption so the ATI DCT will still work fine for them, it even still works fine on my FiOS (they haven't made changes in my market).

The SD HDprime if the proposed price stays the same will beat the Ceton on price per tuner (not know what the up coming 2 and 6 tuner Ceton pricing will be or if the 4 tuner will come down) however they still need cablelabs cert, to complete beta testing and then start production, hopefully they'll be able to meet the demand better than Ceton once they finally release the tuners but at this time we don't know when that will be.