If these are the ones off my car (which I'm guessing they may be) you will not make 450+kw with them unless you go all out porting the head etc.
They made 530rwhp on my car on 24psi. Stock head, stock cams. They hit HARD at 5500rpm and are a lot of fun.
As for an overall setup, I prefer the T04Z I have now, as it seems a bit more responsive and makes closer to 600rwhp, albeit it's a bit more linear.
These twins will be great, but you need to spend the coin on the head to make them work.