2002 Galant performance

Hey all,
I have a 2002 Galant LS auto 3.0 liter V6 with about 25,000 miles on it. I have been having trouble finding performance parts and even much discussion on what I need to know. I have looked through galantspeed.com, but not much helped me there.

I am curious what the best price/performance upgrades I can do without making the engine wear quicker. I would like to add about 30 to 50 more horsepower, but would still like the car to last 100,000 miles.

Any help would be greatly appreciated.

Thanks

I have had my 2002 galant es for a year and the first performance parts I added was an injen cold air intake system and OBX racing headers. Those additions have boosted my horsepower by around 20 hp. I also did a performance oil change using royal purple synthetic.