I am currently producing very alike assemblies via complete reconstruction of individual parts, then piecing together the assembly. I would like to be able to make a configurable assembly file that i can copy (or pack and go?) so i can type in some numbers and hit some dropdowns for specific components. 

For context, the design is a flat square grid made of tube metal with vertical "posts" made of tube metal as well. Those posts each get a cap that can be one of 12 different caps. The outer border of tube metal for the grid is a different size than the inner pieces, Also, each of these pieces of tube metal can be different wall thicknesses based off of a "gauge" nomenclature. 

Ideally i would be able copy the master assembly, paste it in a new job folder, open the file, specify the overall width and depth, specify the size of tube for a handful of components, specify the gauge of tube for each of those components via a dropdown that says "'XX' gauge", choose a cap version from a dropdown, and save it to where i have an independent assy file and part files that will not alter the master file or any other job. 

I have a good grasp of the equations tab for individual parts, but setting things up like that for an assembly has not worked well for me. Im used to inventor's parameter driven area and iParts, and i think my answer might be in a configuration manager situation, but im very lost and not having much luck fonding the answers im looking for. Can someone please provide some guidance or reference materials set up the functionalities im describing?