I have the Russian TEM2 pack, but haven't learned yet how to get it in the game after installing.
http://railroadsim.net/en/presentation-rrs-tem2-pack1-for-railworks
http://www.youtube.com/watch?v=Ou8nt3KQUsE&feature=relmfu
http://www.youtube.com/watch?v=fzBWNolUu48&feature=channel_video_title
The model by it self is as realistic as possible, moreover it's for free.