The engine loom is the same, only there is an 'extra' loom to control the turbo.
I looked into doing a turbo conversion. And it was a pretty easy job and woulda cost very little.
You do not need to run a turbo
ECU. As long as you have something like a flash tuner, and a boost controller it'll work. Custom tunes are a must.
COuple of issues are the sump will need to be drilled and tapped for the oil drain line. And due to the higher compression of the N/A motor, boost levels must be kept lowish so as not to lunch it.
If anyone wants to know more, PM me. If you were gonna go turbo, but didnt want to buy a new car,doing the conversion would be the easiest solution.
Doing a transplant would just be a waste and not very cost effective.
Edit:- As far as I am aware, the 4spd autos are the same in N/A and T models. Only difference in driveline is the turbos come with a solid drive shaft (n/a's have a hollow) and LSD as standard.