engine
The quake2 package will automatically pull the best available Quake2 engine.
commercial game data
Game-Data-Packager can be used to automate the installation of the shareware & full game.
alternative data possibility
Quetoo is a "quake2-compatible game" - http://jdolan.dyndns.org/trac/wiki/Quetoo word on the street is this contains critical security fixes to problems that exist in the above. Rumour is it's dead upstream, but the timeline seems to be updated...
CategoryGame | CategoryGameFPS | ?CategoryGameProprietary