Build scene for a game using Unity

I need a game built in sections because it has to be integrated with other portions of a larger project. The first part of the game I need built is the first scene without props and buildings (just terrain, water, sky and weather effects). I want it built in Unity. If you do well with this project, I will hire you for the other portions of the game that I will need built later (props, characters, character interactions, animations, etc.). Your bid should be for just this project, however. The scene needs to include the following: Large terrain that follows a map I will give you. The terrain will be about 100 times the size of the default terrain size in Unity. Realistic water effects. Realistic sun/star/moon effects (that change with the time of day) Weather that changes on a semi-random basis (rain, snow, thunder/lightning, clouds and sun) The ability to tour the terrain in a first person mode (this will be replaced in a later version with a customized character). You will deliver the project to me as a series of Unity files, but the files should be built with web deployment in mind.