Don't bother looking at plasma's used to be that plasma was better if you went over 32" not so anymore, unless you're looking at very large screens. which you ain't.
I'd go LG or Samsung re quality, cost. DONT listen to a sales guy if he's trying to sell you the 'new' LED technology, scam IMO.
Look at what inputs you might need to be using. Make sure it's at least 100Hz and 1080p. You'll need to get at least 37" if you want to get true 1080P without using software to display it on a smaller screen. Also you might want to research what viewing distance the TVs are supposed to be at.
The '2-to-5' Principle
Blue bullet
For optimum TV viewing distance, the nearest seating position should be limited to approximately twice the screen width while the furthest seating position should be no more than five times the width of your screen.