I can't speak for the Zed, but I have added an expensive forced induction modification to a previously NA car in the past. From that experience, I would say that unless you're intending to keep the car for a long time or really get a massive buzz from doing the work yourself, then you will always be better off just buying a quicker car in the first place. I did that eventually, but not before spunking a good few grand up the wall.
The man-math will never work, so it's a leap of faith into the deep for a passion. If you love the car, then do it. If you have any doubt, don't.