I say stay away from Hitachi and Toshiba. Neither sets do 480p nativly. They show many artifats from their cheap scalers. Every signal sent them except for 1080i goes through the scaler. I have calibrated many sets and though calibration improves them nothing can improve the scaler unless you...
You can use a VINEGAR based windex type cleaner. Basically stay away from alcohol and ammonia. They will dry out the lexan (plastic) over time and cause a fogging and fine cracks. Now when the kids grow up you will want to remove the lexan altogether for a much better viewing experience.