Rainscreen wall type

[dj3862]

I can't find any standard wall types that fits my clients design for a custom designed rainscreen style wall. So,I'll have to create my own wall type. Where can I find information to learn how to create a wall types from scratch? The challenge is the veneer consisting of 12" wide cedar planks alternating with 7" wide planks with 1/2" gaps installed over furring strips. The structure and insulation is easily built from standard wall materials. Any help is appreciated!