Just found a website called OpenGameArt which had this pretty sweet seamless texture pack, which are required for mapping so that your brushes don't look terrible (case in point: SCP-020's texture is not seamless so it looks kind-of bad).
Just thought I'd share that here for anyone doing mapping projects. No clue if any textures in that specific pack will be helpful, but it's a pretty cool site so there's probably more textures on there
