I think you have a better understanding than most about the "how" of doing all this. Since you already have completed your store for physical products, I would say try to add relevant content right to that site, with a focus on the "why" of your niche. Some people will come via paid traffic just for the physical product, but will stay or will come again if there is great content. Other people will come via organic growth if you have great content, but as you point out they will then discover the physical products that match their interest. Shopping tabs make sense for those who want to browse or sort products, but include plenty of links within your written content as well to the pages of the products you are discussing.

I like what ED has said and I would say exactly the same - two out of two

I don't see any problem with a niche site and a product or two to sell also. It creates a store-like environment. Go for it Gerald!
Ed