Hi, actually you have a lot of choices. Anyway it is of great importance to decide what level of detailing you are going to choose. I guess you have to produce shop drawings yourself either in revit or acad.
Depending on what you are going to use your model for you can follow two paths.
a) do a rough model and produce shop drawings with acad
b) do a detailed model and produce shop drawings in revit
Well, it would also be important to find out the need for scheduling parts.
If you choose b) then I would start with planning how those structural parts should be produced and based on that decide the assemblies. Unfortunately revit has not yet suitable tools for model detailing which means that it is not that easy to do a rough model and then using detailing extensions to do connections.
I suggest that you should use structural columns, beams and walls to model the basic structure. Do your own connection parts based on generic model families. Start modelling type parts; full column with connection parts, holes, base plates etc and make an assembly of that. Copy it and where needed make a new one based on the type assembly. For wall panels you can use all modify tools as split, cut, add extrusion or voids forms.
Anway I would base my work on assemblies.
