3d model of a track for a racing game

Hello, I need a 3d model of a track for a racing game . This will be the first of another 3 to 4 tracks for this game,and many others for future games, if the quality of the model done will be good. The game is a kind of rally and the surface is offroad type (ground). I need something similar to the tracks of the game Colin Mac Rae but on a smaller number of polygons because the game will run onto iPhone. The polygon count should vary between 8000 to 12000 polys and only triangles and quads can be used,choosing quads over triangles where possible, ? The model should be constructed in a way that the road is surrounded by a 'wall' of polygons. I will give you a sample model to understand what I mean. It should have altimetric variations and contain a nice number of elements like a small town ,bridges etc etc. The final model must be provided in AC3D format ,which is a shareware 3d editor. I can provide a package of textures if needed.