Okay, so I'm looking at purchasing a bunch of Ork and Eldar models (around 2000 points each) however, I'm not sure how exactly to form companies for either armies. I was given the impression that orks don't really have one, but beyond that I'm not sure. Also, this is for net40k, if that helps any. I'm also not looking at any particular formation or list, I just need to know how to actually set it up.
Thanks a bunch!