I used to have the Majestic Dash 8 300 on FS2004. It was pretty good and includes all of the instrument/overhead panels etc with working switches and systems. It had some inaccuracies that you probably wouldn't notice but once fixed improved the sim a lot. The major ones were that the nose-wheel steering didn't have enough movement so you couldn't turn tight enough on the ground and the nose attitude was wrong in flight (nose at about 0º in the cruise instead of 2.5º-3º) Both of those were easily fixed in the config file.