I will be perhaps controversial but at that age you can simply get any lightweight stroller. Although the recommendation is for babies to sleep lying flat until 6 months of age, it won’t be a problem if your child naps in one that doesn’t fully recline for a few days on holiday, especially as they are nearly 5 months old.
A lot of people really like babyzen yo-yo buggies because they fold really small so you can put them in overhead lockers, but there are now cheaper alternatives as competitors have caught on. Google “babyzen yo-yo alternatives”. Also, for a sturdy and reliable option, many people have a lightweight Maclaren, they are relatively cheap and there are plenty second-hand ones. You can check the relative weight and features of different models. They don’t fold into overhead locker size so need to be checked in.