Why u say it would pop? people is tunning the duratec 2.0 focus in US far more than 200hp, what's the compression ration on Duratec St? the US Focus is at 10.0:1.
The best way to go is cosworth d-power, they don't need to reengineer anything, since the 2.3 and 2.0's are identical from heads to bottom, except deck height, and from what i have read, should make output close to the 2.3, altough you may need to rev a bit more.
If compression is higher than 10:1 then there is a problem for forced induction, 6psi boost maximum, and that's not worth it for what a turbo/supercharger kit costs, you can always lower compression, but losing power for gaining power is not smart for me.
Lucky me......i got zetec 2.0 and i can get the powerworks kit, i'm saving right now
http://www.focussport.com/supercharger.htm (2nd kit)....220hp at the wheels, developed by the guys at cosworth...yummy.