This is based off some comments in http://portingteam.com/files/file/7570-system-shock-2/
- go buy http://www.gog.com/gamecard/system_shock_2
- Get wineskin
- install engine 1.5.23, wrapper 2.5.8 by clicking on the things in wineskin
- create empty wrapper
- open wrapper, click "install yada yada" button, point at setup_system_shock2_2.0.0.9.exe
- that will run the installer, change the install dir to c:\SShock2
- when that finishes, quit out of it
- re-open your wine wrapper and under advanced tick the box that says "use start.exe", i also changed the text box to point at sshock2.exe but not sure it's necessary