Best Upgrades for a 1994 Carrera 2 - Looking to Boost Horsepower

I'm looking to upgrade my '94 Carrera 2 and boost horsepower. Considering swapping the factory exhaust system for a high-flow unit, upgrading the air intake with a cold air box, and maybe even porting the cylinder head. Any experienced members have thoughts on what would be most effective or any specific upgrades I should prioritize?