Yeah Ive been watching that deal at Nengun for ages, I think thats the way to go if you dont want to go down the GCG path. GTRS turbo kit, PFC and controller and 6 injectors for under 5k delivered is pretty cheap.
Saying that there is no real cheap way to get that power target because as soon as you start changing the turbo and boost settings away from the factory settings expect to pay more money for support systems, tuning and maintenance etc. Plus whats cheap for someone is expensive to someone else.