It's easy to run up a huge labor bill for that sort of thing, especially if you go to an quality cabinet shop or RV remodeling specialist. Besides the cabinet work, you are adding power wiring for tv & lift plus tv signal cabling (Satellite/DVD/antenna). A lot of detail work you no doubt want to be nicely hidden.
After getting price quotes, a friend of mine decided on a simpler solution: he bought a 37" tv that he sets either behind a sofa or on the dashboard up front and runs a satellite coax cable from the factory tv location when in use. When traveling, the tv lays face down on a bed and the cable is coiled up and put in a drawer. Crude but cheap & easy...