What are you making this game with?
It doesn't sound like it's going to be a small project.
I have a lot of tools to make it but after the models and textures, I might find out how to use Torque. I also know a friend who says that he can get me UnrealEngine 2 so I hope he can. If none of those work, I hope GameMaker 8 Pro would hold up to the task.
If you want to know the textures and modeling tools I use, they are Gimp for textures and Wings3D for models.