Yes the classic Land Rovers are good choice, particularly in rural areas of Costa Rica. You might also consider the old Toyota Land Cruisers, that are very similar. You might find parts are less expensive and more readily available than for the Land Rover.
We have two articles on importing a car and buying a car in Costa Rica to recommend:
Buying a car in Costa Rica – Top Tips to a Successful Purchase What kind of car should you buy? Gasoline or Diesel? What brands are good for Costa Rica?
Costa Rica Duties, Vehicles to find an interesting article about bringing personal items to Costa Rica through customs, especially vehicles.