I'm not 100% positive for cable, but if you want HD, you need you digital cable box, so you would still need something like an EyeTV HD box. This also works for satellite, so if you ever switch you are still set! For you I really like this EyeTV HD box. It wasn't available two years ago when I was setting my stuff up. As then you get the box, and the software all that works awesome with your Macs. I use the EyeTV software, and it is good stuff!
Overview EyeTV HD
Hook the box up to your cable, then run to your computer. In your case you have your MacBook Pro that you can bring over to your TV, plug the USB into the MacBook and there you go!!
As far as space that it takes up, it is considerable. Before I remove the TV commercials it is about 17-18 GB, after I remove the commercials it is about 13-14 GB. The nice thing is you can export the video in different formats to take up less space. So after I remove the commercial I export the video at 1280 x 720 (720P). That is usually about 4-5 GB, which is a lot more manageable. You could export it in even less quality and take up less space, but what is the point of going through all of this for less than an HD picture on your computer!! I keep both personally, so I use about 17-18 GB per game of hard drive space.
Now what you do to store that video, and then back it up is up to you. I have a RAID server that I put mine onto that currently has 2 TB that is mirrored to another hard drive, and then I can expand up to 4 TB in the future if needed. All backed up in case of a hard drive failure (I have lost data in the past, and I won't lose it again!!).
Hope this helps!
