Figured i would bump this up again, and throw on some links.
http://www.orbithangar.com/
Best place to find mods and other stuff
http://orbiter.dansteph.com/index.php
Home of orbitersound (which is a must have) and delta glider III and IV
http://www.ibiblio.org/mscorbit/
Meadville Space Center (Check the sourceforge site link for downloads). Projects Mercury and Gemini, and Earth 1962 found here.
http://sourceforge.net/projects/nassp/
Home of Project Apollo (NASSP)
http://www.orbithangar.com/searchaut...earch=david413
Shuttle Fleet Package