I have heard some more high class areas like Port El Kantaoui have drinkable water from the tap.
Which areas are safe? Or would it be advisable to buy a small gas stove for my entire North Africa trip?
Tunisia has put a lot of effort into providing safe drinking water and it is generally accepted the water in major urban areas is safe to drink from the tap - BUT travellers report it is heavily chlorinated (smells like bleach) and can cause stomach upset.
Outside the urban areas it is recommended you boil all tap water.
Boiling is the best, easiest option, but not the most effective way to purify water (it must also be filtered to be "pure").
Fortunately, clean bottled water is plentiful and cheap in Tunisia. Even in the cities you'll be offered bottled water at cafes and restaurants.
Unless you're opposed to it on environmental grounds, maybe replace the weight (and inconvenience) of a gas stove with a litre or two of bottled water. Phil almost 10 years ago