96 strat engine swap advice/suggestions

Currently, i am assisting my brother w/ some background research in hopes to swap his factory 150k mi 2.0L(131 hp) (5-spd) with a slightly larger one for....obviously more HP. I was wondering if anyone else has had great success w/ a certain engine, such as the 2.5L v6 in the 97 stat (168hp) Anything that would be able to produce more than 160+HP would be ideal. Any advice??