To be honest, I don't fully understand what your idea is.
Do you want to allow players to decide what the needs are that need to be fulfilled? To replace e.g. fish with canned food for Farmers? Or give investors some beer instead of chocolate?
Or is it about categories, i.e. "they want food, but I can give them whatever I want as long as it's a food item"?
In both situations, there's a big balance question, since the efforts to create specific products of course greatly varies (i.e. champagne vs fish), which is currently reflected in the way these products are assigned to specific population tiers and the effects they have for the respective population tier.
That would require a very flexible system that has different values for each product for each population tier - and there are many open questions like: do Investors even get any bonus from fish, considering its super low production effort?