There are still small shops around
You just have to live in major metropolitan areas for this to be more widely common. Again, this might mean you drive an hour to see HDTVs. OK. Worth it though so you don't get the crap on the poorly designed sales floors of BB, Sears etc.
When you mention you would like 50-55" HDTVs, you *are* looking at large screen HDTVs that are discussed ad nauseum on such aforementioned forums. Spend some time there and you will see that they discuss all types of equipment, shapes/sizes/brands/models/price ranges. It's not only the 100" high end panels. The quality has changed, so you definitely wont' be getting the fuzzy dim beast you used to own .
If you have any sort of direct bright light, all bets are off unfortunately. All large HDTV panels will requires some type of window treatments/room darkeners/shades for optimal viewing. Even LED models that can handle bright roooms (within reason) better than plasma can only fight so much against the reflections of such a large screen. If you *can* lower the room light to reasonable levels, plasma is a better all around bargain, especially a couple of the Panasonic models depending on which features you need ASAP, or can bolt on later with other equipment. Dollar for dollar/feature for feature, I'd look at the Panasonic ST50 in 50 or 55" sizes. If the room's still quite bright, look at some of the higher end Samsung LED models, which generally can handle bright spaces a bit better. YMMV. It's partially going to have a little to do with one's viewing habits and preferences. I simply hate any sort of content being 'washed out', so I need more of a 'man cave' type environment for my viewing. Room darkening shades let me keep my plasma in a more central location.