Couple of ideas:

Quicksmart Fold Away- folds down smaller than a traditional stroller and even comes with a bag to put the stroller in. Absolutely ideal for travelling. 6mths to 15kg. Weighs 6kg

Chicco Liteway- folds like a traditional stroller, locks when closed, meaning you can pick it up on any end. Birth to 20kg. Weighs 6.9kg

Steelcraft Phoenix- folds like a traditonal stroller, doesn't lock, but is also the cheaper of the 3. Newborn to 17kg. Weighs 7.5kg