Personally i think the idea of swapping engines will just be a waste of time, like many others have said there will be lots of issues which will all require cash so you will be better off putting the money towards either a charger or turbo. Then when it comes to selling it that will be a big ballache.
We have built and look after a mk4 r32 running a huge turbo which is only currently 450hp and its awesome
. This winter its going for a complete rebuild and setup to produce around the 600hp and its going to be imense
.
Personally i prefere turbo over charger but it all depends on what you want out of your car.