It sounds like what you have laid out will look lovely! Do you have a picture to share?

Our tile installers on staff always shuffle around natural stone tiles to make the space look varied and even throughout. This way, you don't have all of the "heavy veining" tiles in one section and the "minimal veining" tiles in another. You want it to look natural and thoroughly mixed. Also, be sure to seal the tiles with a good natural stone sealer three times throughout the installation process. Once when they are laid out in the space, another time after the tiles are set, and then lastly after they are grouted. This will protect the tiles (and grout) for a while. Best of luck!

Attached is a image that designer from retail store provided me. My phone battery died on me so I was not able to take any photos last night.

We will not have more than two widths of tile total, unlike this image showing three 12x12's.

Your comments about sealing is interesting. I have not had anyone share that information but up until now we have worked with strictly ceramic and porcelain tile.

Is this sealant recommendation only on natural stone tile...like the marble? We are also planning on doing a river rock mosaic tile as backsplash. Should this be sealed as well?

The sample image is very beautiful. You are correct -- sealing is only recommended on natural stone tile (such as travertine, marble, granite, etc.) If you had only used porcelain or ceramic tile before, it would not have been mentioned to you. Natural stone is porous, unlike the ceramic or porcelain products. Sealing helps to prevent staining of any kind. An impregnating sealer is the best kind to use, for it will soak into the stone and help to stop any other liquids or items from doing so. The retail store where you purchased the tile may even sell a sealer. You probably could seal the river rock, but I would not be as concerned about that material. It is not going to receive as much use since it is only a backsplash. Are you installing that yourself as well? It is a more difficult material to work with, so I would be sure to follow any recommendations or advice from the manufacturer.

we are installing the river rock mosaic as well. Actually, the river rock in the mosaic is sliced so surface is level unlike using the whole rock.

I've done some online research on "how to" and found some very helpful videos on youtube. Lowes.com had an excellent "how to" video.

Oh good! That will make it much easier. Good luck on this project! Be sure to post photos once you are finished :)