LED is nothing more than an LCD but with an LED backlight system instead of small strip lights (like the ones that you find in a kitchen or garage). Therefore LED (read LCD) is actually older tech than Plasma. Reflections can be a problem but with the latest generations it's not so bad, combine that with a little common sense (don't place it opposite a window for example) and you will be fine.
The future is actually 4K OLED which is drop dead gorgeous with a mind blowing picture but......... It's at least 12 months away. So many things have to change to make 4K viable.
Better compression systems are in development (a lot have been confirmed but will need to be put into practice), with these it will make terrestrial TV possible (Japan are trailing this now and Sony/BBC are experimenting at Wimbledon as I write). I also read yesterday that a new WiFi platform has just been agreed to make 4K streaming around the home a possibility) (great, that means I have to buy another router).
Then the real problems will need to be tackled, Broadband speed will probably be the most important thing that will need to change as the amount of data needed for a movie is huge (around 500gb using traditional compression for a 2.5hour movie). If we believe that our movie and TV viewing future is via the internet that is.
Clearly, 500gb does not fit on BD disc, even if it was capable of 4K (it's not, as it was never in the original agreement/specification) and also HDMI is technically capable of carrying the data needed but it is not ratified to carry native 4K content (yes it can do upscaled) and this will be solved by the introduction of HDMI 2.0. However this will not happen until next year so that lovely 4K Sony TV thats at the front of a lot of Curry's stores at the mo, is almost useless already, or the 4K LG in Richer Sounds.
Anyway, rant over.......Get yourself a 42" GT50(if you can find one) or GT60 ( if you can afford it ) You will not regret it. As far as size is concerned the general rule of thumb is that for 2D you should sit 3 times the size of your TV away and for 3D it should be 1.5 times the away, i.e. if you buy a 42" you should sit 10ft away for 2D and 5ft for 3D so at 8ft away you should have a very happy compromise!
Also, if you go to a panasonic store I believe you can get a 5 yr G'tee.
TA