Hey guys I want to know what are some ways that I can rebuild my engine later on due to High milage. I have a WRX for 8 months now and have over 15k miles. at this rate when I actually own the car it will have 100k+ miles. I dont wanna turn the engine to much at that point though. So my ? is:

What internals or modifications would you make to the engine. I only want approx 250-280whp when its all said and done. I know nothing about the Ej20 so please be gentle. I do have the understanding of engines though.