Little on the theoretical side and I also have no idea what I'm talking about... but would it be at all possible to have a smaller primary turbo to handle the lowend rpm's and the larger twin turbos for the higher end, each dealing with 2 cylinders? Supposing I have any idea what I'm talking about and there's enough space to fit them.

I don't know, it's off topic a bit and probably makes about as much sence as me asking if write TURBO GAS on a can of Coke and pour it in my tank will it make be go faster.