Rob why would you do that over a twin system for that amount of output. Just to change the manifolds, oil and water lines, exhaust, external waste gate going to cost a lot more than 2 replacement garrets or such.
You could just bolt on some 2860-5, Power FC, adjustable cam gears, decent tune and you will make that number or get close with a stock engine. Then again i am sure you have your reasons and if you have the cash mate fill ya boots.