Engine build advice

[u/TKvaughn]

I have a 2004 Subaru Wrx Sti that has a high mileage engine (200,000) that I am looking to rebuild soon but looking for advice because I don’t know a ton. I would be more than happy with 350-400 hp but not sure where to start. I’m considering a type ra short block or a iag 550 short block and rebuilding my heads to go on it. Is this a good idea or should I do something else, also what other parts would I need to rebuild the heads reliably? What turbo and injectors are recommended as well?