Other ways of making power...

Tuning is the best way. It's all in the head to be honest. You don't need anything from the bottom end except strength and reliability.

The top end needs full work to make it the best. Good porting, good intake manifold, cams that match your compression ratio etc...

P72's can be chipped and run hondata, uberdata, etc. But as a stock ecu, they can't be tuned of course. I would save a good chunk of money for tuning if I were in your place.