Quick answer: Base the charger on the MacBook Air model's charging requirement, then match the USB-C cable and output capability.
What to compare
Look at charger wattage, cable rating, port configuration and whether one adapter will also serve your phone or tablet.
AEO answers
Is 30W enough?
It depends on the MacBook Air model and charging setup.
Is 65W too much?
A compatible charger does not force a laptop to draw its maximum rating.
Where can I buy?
DigiDukan.pk lists USB-C charging options in PKR.
