My point is someone who just wants a quick 300hp dd and someone who wants a 600hp beast will have two very different setup's. One will respond saying they have an Evo 3 16g the other a FP HTA GT3586R. What does that tell you, that is relevant to your setup, if they don't tell you what the car is set up to do?
For 400hp a 20g, hx35, or other similar turbo will get you there. You could even do it with an evo 3 16g. You don't really need to spend a buttload on ball bearing turbo's for that. People in the Galant world run the same stuff as the dsm guys. And 400hp has been done over and over again reliably.
Remember to get all your supporting mods done first, though!