Don't trust those chips on an N/A car. There's hardly any settings it can adjust other than the amount of fuel delivered at any given time.
Least with a remap it can adjust the ignition timing to get more power from it rather than the amount of fuel by richening the mixture past the standard 14.7:1 ratio.
On turbo car's you can adjust boost but no turbo on a N/A engine.
Its difficult becasue all you are trying to do is get air in and out the engine as fast as possible.
The biggest limitation is Bore x Stroke size. Without increasing this the engine will always have a compromise somewhere.
You go for aggressive cams with large overlap - you get plenty of peak power and torque but little else (Great if the car spends its live above 5K) but unless its on a track you wont be doing that.
The best bang for buck you can really do is - Air intake, 2.0 Cams and a remap if your wallet allows.
Anything else you will be scrabbling around for 1-3hp gains at a large cost.
Alfa 166 2.0 Twinnie - LPG and a few trick performance parts