I went for a ride in a 650hp twin turbo camaro and it scared the shizz out out me. Wasn't exactly my idea of a daily driver..
For daily driving I would stick to low boost and you don't really need an insanely built motor for that.
If I were you (assuming I was spending my money...you may have tons more) I would drop a 6.0 Iron block and 8PSI and call it a day. Once you get over a certain HP it is useless if you can't get it all to the ground.
EDIT: I just re-read your post. 471rwhp with a turbo kits seems low. Is this because it is a rear mount or is the PSI really low?