Well with my research on this fantastic site, I think I am going to use substrate under the live rock, and have the 12"x12" travertine tiles on the front part for ease of cleaning. My husband started playing with the 1"x1" travertine squares to build dividing wall to hold the substrate back from the marble. It is looking good but I am thinking that perhaps I should take some broken pieces and build the wall with that to compare the look. The little squares will be much easier to silicone together, but I have the day off, so I am like a kid with Lego. Nothing is siliconed yet (ran out and have to drive into Calgary for more), and some of the travertine is wet which shows up darker in the pictures.
I cannot post the pics here so they are in my flickr account. What do you all think? I am still learning how to use this account since I just started it last night so the pictures are all over the place. Sorry about the mayhem. Any comments, ideas or suggestions would be much appreciated since we only want to do this ONCE.
http://www.flickr.com/photos/30861436@N08/