I have SS2, how about SS1, Gog?
Not really necessary. SS1 has been freely available for some time.
http://www.systemshock.org/index.php/topic,211.0.html
Still, I wouldn't mind seeing it on a site like GOG just to make more people aware of it.
I wish someone would remake SS1. The graphics border on unplayable now, but the game itself is incredible. I regularly fire it up in Dosbox.
Have you tried SS Portable? (above link) You can run it in higher resolutions than the original version. It makes a significant difference.