25 Apr 2012 EDIT: Arby26's better MP5s can be found here:
http://l4d2.gamebanana.com/skins/116639
25 May 2011 EDIT: DL links!
http://l4d2.gamebanana.com/gamefiles/2219
CS weapons
http://l4d2.gamebanana.com/gamefiles/2218
M60 Replacements
http://l4d2.gamebanana.com/gamefiles/2217
China Lake Grenade Launcher (functionally, not cosmetically!)
http://l4d2.gamebanana.com/gamefiles/2216
Melee Backup
http://l4d2.gamebanana.com/gamefiles/2220
Melee Substitutions
http://l4d2.gamebanana.com/gamefiles/2215
Automatics as Sidearms
Rather than try and use the console to spawn a weapon that doesn't fire or can't be used until the next safe room, I looked around and found the models, textures, etc for the "unused" international weapons from Counter Strike: Source supposedly only available to some of the international copies of the game.
I vpk'd the findings to make it easy to toggle in the Extras-Add-ons menu. For the spawn-from-console stuff, I suggest lupe121283's video on the subject.
