Is it possible to use other products (entities) as a kind of "attributes" or "sub-products" for a certain product?

Let's say we have a "base computer", We call it "Product A" (product entity). Then we have different hard disks, which we can call "Product B1", "Product B2", and "Product B3" (all product entities). Al of this products can be bought separately.

When the customer looks at the display page for "Product A", he should be able to choose if he wants to add any of the "B" products to "Product A". If he does, then the price on the page should update.

How does one implement this? Maybe I just miss something simple? It is something of a mix between attributes and related products. And this is, I think, a rather common feature, in the world of e-commerce. I don't think I can use the standard attribute feature, since in my scenario we are not only talking about different SKUs but a combination of different SKUs.