Irrlicht Engine

Hi,

Lets say I'm making a voxel FPS. I'm thinking Ace of Spades or Brick Force. What libraries or engines go nicely with Irrlicht to achieve my goal of making a clone of one of these?

What libraries or engines I already know I need:
Physics
Sound
Voxel(maybe)

for voxel i prefer polyvox
http://www.volumesoffun.com/polyvox-about/
if you want to make a game like your examples polyvox owns a class CubicSurfaceExtractorWithNormals that is very good for such things ( http://www.volumesoffun.com/polyvox/doc ... rmals.html )