Hey,
The trouble with rings like this is that getting into orbit covers much larger distances, so being accurate enough with your ascent to hit rings is a very hard prospect. In Orbit it could be almost impossible to do. So, I think such a thing only really has a place for atmospheric flight.
To that end, check out [ame="http://www.orbithangar.com/searchid.php?ID=4126"]Orbiter Racing League (offline v1.1)[/ame] It has all the components you need to do rings, you would just have to change the gate meshes for ring meshes.