Welcome to Simviation. As someone that uses FS2004 I can say it has been a dream to get the RAH-66. The last one that was made was for FS2002 or 2000. Either way there is not ONE for either of us. It would be nice though.
If someone made one that was compatible with both, it would serve both of our requests. The problem is that it take a HUGE amount of time to make an aircraft for FS. I know nothing about modeling so I can't really help.

Hopefully someday we will have one. Kind regards, Jeremy