from reputable manufacturers...
Sony VGA 42-inch plasma includes a video board but does not come with a TV tuner - this may be more appropriate for your office than a model that does have this TV tuning facility.
Sont FWD-42PV1/S Plasma Display
Sony VGA 42-inch plasma entails a video board however it unusually has no TV tuner - in many respects this can make it more suited to your business.
Sony FWD-42PX2 Plasma Display
Sony XGA 42-inch plasma includes a video board in addition to a DVI connection yet this product too has no TV tuner enabling Sony to focus on business requirements only.
Sony XGA 50-inch plasma includes BKM-FW10 video board, optional speakers and often comes with a two year swap warranty. This relieves those opting to use this product in business applications.