@Kadri
Yeah, I have a pretty good idea of what I want. I started my own thread before I was directed to this one here
http://forums.planetside.co.uk/index.php?topic=7902.0. If you look at my first post it has a link to a zip with my terragen file so far (before I started messing with these craters) and a sample render of what it looks like. I'm basically going for as photo-real as possible both from a few hundred kilometers up from the surface down to the inch on the lunar surface. Now, i'm by no means trying to create an exact replica in 3d of the actual surface of the moon, but it needs to look convincing enough to pass for the real thing to the average joe. Shouldn't be too hard, I have complete confidence in Terragen...but I'm still trying to wrap my head around these node setups. I'm only really used to material nodes in 3d, not procedural mathematical nodes, so its a bit convoluted right now. But the end goal, as you can see in that link, is to create a 3d moon in Terragen which will allow me to basically go as far out or as close in as I need to as I place my own imported 3d objects on the terrain for my project. That's why I think it's a better idea to stay almost 100% procedural because it will free me up from having to paint another displacement map any time I want to move to a new area, or make it look like i'm moving to a new area. Anyways, I hope all this is clear...
I tend to ramble on and on. Thanks for your help again guys!