I have some doom2 sprites that are all in PNG format (Same names as the originals, just in PNG format instead of bmp). How Can Vavoom load these PNG sprites externally without having to put them in a wad file? How do I set them up to be used externally if possible?

Vavoom does not need wad files anymore, it uses pk3 packages. Simple create a pk3 package called sprites. Inside should be a folder named "sprites" and this folder will contain your PNGs. Same thing could be done with whatever data you want: textures, maps, misc graphics, sounds, music etc.

Thanks! I will post up some pics of 'Fallen' shortly in the projects section soon!