Thanks TJ, Reckers!
I'm not sure at this point, whether I'll even want water/ravines. I just don't want to be tearing it all out at a later date to add them. I was talking with, "The Boss" last night, and went on-line to show her some of the cool set-ups. She loved the "Towns", I like "Industrial", so we agreed that we should try to combine both and I mentioned having a "Waterway" as a way to keep them separate.
Considering all of that, would a 2" base with a 1" top be the best way to go?