What do I need to do to build a 1000hp turbo small block

Im not familiar with the gen 3 hemi.
Gen3 Hemi is what you called a 6.1 or 6.4... the new generation of hemis in new Challengers, Chargers etc.
You can buy them as crate engines but then your son's budget is gone. In the US you can already find them
in wrecking yards... (I read, since I live in Europe :))
What is he going to do with his car... occasional street racing, an occasional trip to the track or burnout contests
with extended high rpm's?