You're correct in eliminating plasmas. You definitely want an LCD for that type of room if you're going with a flat panel. My LCD is right next to a sliding glass door, and I notice less glare than my old CRT tube I used to have there.

I've never had a westinghouse, but known some people who have been happy with theirs. I have an LG, and highly recommend those, but they're going to come in more expensive than the Westinghouses. They seem to look pretty decent, though, to me they looked the best in their price range.

There's a few reasons that I would say get the 1080p. At 47" you're probably right where you can start to see the difference. Second most 1080p sets use a frame buffer to make a 1080i image progressive, which is a nice feature in my experience. Finally, you'll not be kicking yourself down the road for saving a few bucks like you might with a 720p display.