motor swaps

i have an 03 cavy and i am wondering wat is the best way to ad power without spendin big coin!? i am also inquiring about motor swaps i kno those cost alot of time and money but there is the possibility that my engine is on its way out and i was thinkin this would be a good time for an upgrade? is the cobalt ss motor a possible swap r am i just chasing the wind on that one? or should i scrap all thoughts and get a better or more tunable car? any help would be amaizing and much appreciated!!!! thanx