Adding some features into my game engine written into C++, C#, and Java

Hi.I’m looking for an expert who has a lot of experience in game development. I would like to have a game engine clone of [login to view URL] I have already the game source related with above, but I cant change some parts, so want to help me. You can see the features of the game following website: [login to view URL] I want you to add several features. - On the game as it stands today, gamer can declare bankruptcy and user airline goes away or if user runs out of “coins” user airline goes away. I want other gamers to have a set time period to bid to purchase that airline before it goes away. - I want to add cargo demand. Current game only shows passenger demand, so airlines to be able to hold cargo as well for additional revenue. - I want to develop by using program language such as C++, C#, and need game design specification (written into UML), before developing this project. Thanks.