N54: 335xi singel turbo

Hi would like to know how good the 335xi powertrain holds. I go single turbo with 6466 turbo 18psi on 93 ron without problems. Now I have bought syvecs pnp and pi and now I intend to charge for 600-700whp. What comes first in the driveline ?. Are there any upgrades to the 335xi powertrain?.

Mvh Niklas