RE: Create an assembly from non-inventory items
I would think the Jobs module would be a much better fit for the Construction industry. The Job is never to make anything, it is essentially a big Service. You can consume Items, Non-Inv. Items, Resources, etc. to track the costs of the project. You can also track your billing to get profitability analysis on the projects. Not to mention far better Estimate vs. Actual comparison using Jobs.
If you are just starting with BC, I would strongly encourage you to look at using the Jobs module instead of the Assembly Mgmt. features.
You should discuss this with your BC Partner to get their input as well.