Gun and player sounds youll have to modify on your own.
The servers sounds are
zbeat1 - 8
wraithdeath1 - 4
lasthuman
humanwin
lose_test
pretty straight forward
The human death sound is one of the citizens, youll have to find out which one and name your own sound file after it and place it through the correct file path in your gmod folder.
The wave sound is called cave_hit1 ---- half life 2/hl2/ambient/atmosphere/cave_hit1