Well of course you will be needing an antenna. Exterior antennas are always better than interior ones but that's a choice...
Your TV is a 1080i TV with no ATSC decoder. You should forget the Zinwell and go for a HDTV ATSC Tuner. There aren't much of these since most TV's since 2005 had a ATSC decoder.
HDTV ATSC converter boxes have either component (YPbPr) outputs or HDMI/DVI outputs that output at 1080i (unlike the Zinwell which outputs at max 480i SDTV).
Consider the CM-7000 PVR which has a HDMI out (use a HDMI to DVI cable for your TV) (400$)
Also the Centronics ZAT-502HD (120$) and the Wineguard RC-1010 (170$) are HDTV ATSC decoders for your TV.
The ZAT-600HD from Zinwell is a good one but is discontinued.
Check this link for more info.http://overtheair.saveandreplay.com/ATSC_Tuners.asp