This might help as to deciding which box you need.

AVS Forum - View Single Post - ATSC Converter Box comparisons

If you read around their forum you can get opinions as to which ones are better quality.
Digital TV (HDTV) - WTFDA Forums

NTIA Requirements for Coupon-Eligible Converter Boxes
NTIA Requirements for Coupon-Eligible Converter Boxes

Locate a Converter Box Retailer near you
https://www.dtv2009.gov/VendorSearch.aspx

The complete list of DTV Certified Converter Box Retailers
http://ezdigitaltv.com/support-files..._retailers.pdf