well how mechanically inclined are you? looking for a turbo setup? for N/A you can put in a 2.5L RS engine 165hp, but other than that there are tons of turbo swaps possible. ej20 swaps (227hp), jdm swaps (250-280hp), usdm 2.5sti swaps (300hp), and the legacy 2.2t swap (160hp+more potential
) (what i have). search around the forums for what suits you best. there will be wiring involved unless you do a N/A setup.