Actually you don't need a AIW for video out as most modern ATI cards support component out, so no reason to get an AIW just for that and if you do want a tuner card then using a separate one has it's advantages as well. Also, Nvidia has some really nice support for avoiding overscan issues and such built right into the drivers, where ATI's fucntionality in that area is notably lacking. Granted, whether you will even need that functionality depends on what display you are using and Powerstrip can do the trick as well, but it is still nice to have such features right in the drivers.
As for Nvidia cards with component out, most don't officially support but there are plenty that do and they are branded "Personal Cinema" cards. However, I do recommend using VGA or DVI if your TV supports either, nothing is inherently better about component and it can be a lot easier to get a PC standards working though a TV than the other way around.