Check BoostAddict's thread (maybe better called a novel) on his upgrades of his 08 WRX. He did a VF52 and he needed to change the injectors. Are you sure that the injectors are the same on an 08 WRX to 09 WRX? I thought they were different. WHP varies significantly depending on the dyno, but we'd be talking somewhere in the range of 230-250 WHP (unless someone corrects me) on a VF52 running stage 2.
Technically, an 08, running an increased size in turbo and intercooler, would be stage 3, no? I mean, it'd be stage 2 on an 09, but I think on an 08 it'd be stage 3. Semantics, I know.