You should have a look at the supplier sites for info as well as the forums. For instance, about three years ago Hitachi were the only company using soft/hardware designed specifically for LCD/plasma TVs, every other company used the internals from standard sets and the visual difference was like night and day. Even the top range Sonys and Panasonics (both 100hz, picture enhancers etc..) looked S%!* by comparison, thats not even taking into account the shops NEVER set up any colour/contrast or brightness settings to give the best picture possible.
Remember to leave about 10% of your budget for cables as the picture/sound is only as good as whats being fed into the set.
After all you wouldn't put standard asda petrol in the Zed?