3D game development

My comp is building a game that will have horse racing, golf, basketball, football, soccer, and baseball. We are starting with horse racing and golf to be released. For starters, I am looking for someone who can build a 3D horse racing track with an grass infield that will be able to be changed with digital art at a later date by my devs. I need to have a gate that the horses come out of with up to 20 spots for horses, be able to move that gate anywhere on the track for different distances, a finish line, and maybe a small side for fans to sit and watch. The stands part needs to be able to be changed by devs as well. If you can also do actual horses on the track that we can change the looks of, that is a bonus. If you are the dev that we pick to run with, we will have a TON more work upcoming for you. We will need 12 total tracks, 18 golf courses, as well as multiple baseball stadiums, basketball arenas, football stadiums, and soccer stadiums all doing the same type of thing. Lots of work coming up. Please let me know what you think. Thank you and have a good day.
Please I will like to see some of your sport project related to this.