Looks like the HD DVR from DirecTV is now $199. I need to pick one up if I get a new HDTV for the home theater and move the old one upstairs.
I, too, am a power Tivo user and I still watch some shows on the SD Tivo and SD 35" Mits CRT just because it's so much easier to use, especially being able to flip between tuners. Be aware with the DirecTV HD DVRs that while you can record 2 shows at once or watch one while recording the other, you can't flip between tuners. If you want to watch 2 shows at once you have to record both and even then I have problems trying to pause one, then switch to the other and back. It doesn't always return to the paused point - it goes to the end of the buffer. Other than that the interface is tolerable.
As for antennas - don't bother with TERK. Looks like all of your DTV channels in Baton Rouge are UHF except the ABC station which is 13 but most UHF antennas can pick up 13 - so just get a good UHF antenna. If you're in the city or close you can probably get by with a set top antenna. If you're further out then look at a channel master 4224 (4 bowtie) or 4228 (8 bowtie) or similar design. You may need a pre-amp if you're really far out. Roof mounting for the outdoor antennas is preferable but the attic will usually work, too.