Congratulations on being on a cutting edge committee! I have a couple of suggestions that might help with the process.

1. Have a good grasp of STEM – what it is, why we need it, what current research says, and how it’s being used successfully in other systems. I have a site where I curate some STEM articles at http://www.scoop.it/t/stem-curriculum. Feel free to use that if it helps.

2, Build the curriculum around an engineering design process. The one I use is pictured in this post. You can Google “engineering design process” for other variations.

3. Plan to make student teamwork a normal part of the curriculum. (This takes time and persistence.) This may mean that you need to teach students how to work successfully in teams. Some cooperative learning techniques help with this. This pdf. may help as well. http://www.middleweb.com/wp-content/uploads/2012/08/7-Student-Teaming-Tips-MW.pdf.

4. Build lessons around a real life problem, and plan for students to work through the steps of finding solutions for several days.

5. Be sure STEM curriculum objectives are build with the science objectives (and math objectives) in mind. If you will be using the NGSS objectives when they are finalized, this will be easier.

6. Plan to field test and revise lessons and curriculum before finalizing it. Hope this helps!