[Stuart]

Beyond actually going into a decent HiFi/Home Cinema shop (preferably not a major high street electrical retailer) and seeing a few to find which you like, I can't really offer much advice. If you have a branch near you, try Sevenoaks HiFi, or Richer Sounds (Richer has the advantage it is cheaper, but they do end-of-line stuff).

As for the difference between LCD and plasma. Plasma gives better colour reproduction, but uses an awful lot of electricity (nearly twice what the equivalent size CRT uses, and four times what the equivalent size LCD uses).