You gotta pay to play... That said, you'll fiind the Poniac not terribly expensive to mod!

best power for the money - Turbo
best backup mod for power - Built Trans
best tuner - HP Tuners
best money saver after modding - Radar Detector!

read the modding 3800 thread...
make a plan, read some more, revisit the plan, but have a plan before you start modding

Cheap/Fast/Reliable
you can have only two at a time, chose wisely ; )