I'm really sorry Kolya, I didn't think of all of that
You're right, it'd be best if the manuals stay here so that SBF can get more attention. What if I upload the English manual and then put a link to all the other manuals and ref cards on SBF in the Rdocs comments section of the manual's page (comments are displayed under the manual info). That way, people would come here for the English ref card and the other languages. System Shock portable is a really cool thing and as you said, a lot of people would be interested in it, if only for the XP compatibility alone.
I can't actually link back here because...well I don't have my own website :p