Both of the mentioned ways would be using the existing 7M-GE that you have, just modifing it so you'd be okay. IIRC, 1/2 NA-->T is using the stock electronics instead of ECU, coil packs, etc. The only difference between the blocks are the N/A have higher compression pistons (which can be a good thing if you arent looking for too much power) and dont have oil squirters, however without oil squirters that oil can go elsewhere to lubricate rather than cool the bottom of the pistons IMHO.

Overall, you'd be best off checking out first hand experiences and asking people how they went about. You may be better off just swapping in the 7M-GTE and going from there, most of the people that go N/A-->T are just doing it to be a bit different and such it seems.

There are some advantages to turboing the 7M-GE, such as the higher compression, the N/A cams (dyno says 10HP everywhere and more torque when you need it), also you shouldnt have to take out the engine from the car.