I've never researched this swap, but figure on
new ecu
new wiring harness
custom wiring work
new mounts, maybe subframe, maybe modification to the firewall, shock towers, anything really- it's far from a bolt in, I'm not sure on what all needs to be done
-new tranny, the engine, new exhaust, new radiator (probably), new axles, might even need new hubs/front suspension (not sure on that one)
-intake piping, intercooler piping, maf, have to get the power steering to interface which means at the least custom lines, maybe the same for the AC, fuel pump, fuel filter might not be in a compatible location- might need all new lines from the tank

The list goes on and on. I know little about 2g cars, especially nt's, but these are the things I came up with off the top of my head that might be different. It's a nightmare project and far from worth it. If you want a turbo NT, turbo the 420. If you want a 4g63, buy a car that comes with one.