NA motor can be turboed and make power, but its often cheaper, better, and stronger, in my opinion and experience to just do the whole l28et engine, unless you have this parts list on hand..
Turbo oil pump
oil pan
injectors
eccs efi harness and sensors
dp
exh manifold and turb0
piecing it together costs more than the turbo setup if you can get one complete, which ive seen anywhere from 150-500.00 and last two parts zxt cars ive had cost me less than 500.00 each, selling parts of the t5 car actually net me a small profit which I used to add a few fresh sensors and parts to the conversion.
Not trying to crush the dream, but it sounds like you want a car that has good zip and is reliable, the stock zxt setup in a z can do that easily, wheras turboing an NA engine opens up more variables that must be addressed due to the car not being initially setup for turbocharging and the addition of a turbo. Not saying it couldnt or shouldnt be done, but this isnt what ive heard, this is what I know.