hi there navqam,
i wouldnt recommend getting the 4 point plugs or the iridium plugs, as im sure u hve the carbeurator version engine, also your engine wouldnt be needing a fuel management system, as mostly its all manual.
To start off with i would recommend getting the original spark plugs according to your vin.
The next step would be changing the jets on the carb, along with a full tune up.
Purchase a high flow race air filter, this will replace the whole air filter housing.
Remove all the filters on your exhaust pipe & install a high flow exhaust.
This will surely help you get a noticeable diff in the power.
As for the plugs, if you are willing to spend alot, get the msg ignition system & the whole kit for the car, otherwise stick to the genuine plugs.
Use a semi Synthetic engine oil 10w-40, which lasts for 10000kms, either magnatec or any other good oil with the similar rating..
hope this helps you with ure mods..