Have you tryed a salvage yard for used engine? Check into a jasper remanufactored engine. Salvage yard should be able to tell you what engine will work. (It is a Nissan engine, Quest and Villager have the samme engine.)
If you would get a used engine consider but in a new timing belt and water pump on while engine is out of vehicle. I would say with engine out it shouldn't take more than hour to change both. Keep us posted.