guys
if the aim is to build a GTS-t to beat a GTR, why not spend the money on more important things like aftermarket management system, along with a big enough turbo to provide the horsepower required. Match it with a good FMIC, high flow exhaust and air filter, and if the standard internals can handle the power gain you will have reached your goal, but more importantly you will have potential for more power gains with a strong rebuild in the future. Unfortunately this will cost you more than $2000, but then again i would love to see a well tuned twin turbo set up on a GTS for $2000.
Sure 'twin turbo' sounds sweet, but cost and hassle aint worth it, and your goal of beating a GTR can be achieved with a single setup.
Horsepower requires money, especially if you like reliability and drivability.