Wow, it's been close to 15 years since we did any sandblasting. Time flies!
I'll throw in a couple of comments (2¢ worth). I would be a bit worried about the effectiveness of some of these layouts on a sandblasted sign, especially one that held a lot of grain in the background. Many would work fine if one a flat surface. For the most part, you have either raised areas or blasted areas. Positive or Negative so to speak. If you have the budget, you can always add raised letters or raised graphics to get another dimension, but some of the layouts I see above back you into a corner. If there are letters over a mountain or another graphic, you have to figure out how you are going to deal with it on a dimensional sign.
Also, despite all the whiz bang elements you might consider adding, you still need to consider contrast values when everything is finished. With light colored (and yellow) sandblasted backgrounds, you end up with quite a bit of shadows in the blasted areas and that can drop the value down quite a bit. It will not really be bright yellow, but a darker shade of yellow. Keep in mind you need either light against dark or dark against light for your main message (signs 101). I also like middle toned backgrounds with light letters and dark outlines. We also found it was safer to have a middle toned background or dark background in the sandblasted areas. If they get darker because of the shadows, it doesn't hurt the legibility if you have light colored graphics. Lastly, white and yellow painted backgrounds on sandblasted signs often take on a plastic look, especially so if painted with glossy paint.
Good luck with the project.
Mike Jackson
www.goldenerastudios.com
www.mikejacksonphotography.com