There was a package called Proflight.
It was originally "payware", but later became "freeware" and was discussed here on the Pro Training Forums.
Quite a nice little package, no visuals at all, so on instruments all the time, but it may be what you are looking for?
I'm sure a search will throw the thread up.
However, FS2004 means you can have a lot more "fun".....
Regards,
Shuttlebus