I seceond your suggestion. A standalone HD tuner would be a very valuable addition to any HT setup. The quality of HD broadcasts exceeds that of Sirius or XM radio IMO, and it doesn't cost anything.

A componant size/appearance of the HD tuner would be another recommendation for such a standalone componant.

The only such tuner I know of is one by Rotel, and THAT retails for around a thousand dollars.