The revamped/reinvented (whichever you prefer) Gateway will present four new TV models this week. After a successful launch, late last year with its first TV set, a 42-inch plasma screen that was priced well below competitors, this time around they will be unveiling two plasma screens and two LCDs. The new TV sets will try to expand company's position on both ends of the consumer spectrum. The LCD sets--an 18-inch and a 17-inch model--are for customers who want to upgrade but aren't ready yet for an expensive plasma set. Both models can double as a PC monitor, and the 17-inch model can be mounted on a wall. The 18-inch set goes on sale Thursday for $899; the 17-inch model will be available for $799 in early August.