I would definitely get a double with those ages..I have a bugaboo donkey and cannot recommend it highly enough! Can have 2 bassinets, 2 seats, one of each, both parents facing, both forward facing, one each way. Also 2 car seats, 1 car seat, 1 normal seats, 1 car seat, one bassinet. U get the gist lol. But the bonus is it can then be used as a single once the eldest no longer needs it, or just wants to use the buggy board etc..not cheap but worth it's weight in gold!
Is the donkey very heavy ? Guna have to go in to shops for a test drive!
I find it the easiest to push and steer by far! I'm a nanny so have used tonnes and tonnes of single and double pushchairs and I love this over them all, so much so I got one for my own!
I have the bugaboo donkey too. Have really enjoyed it for long walks in the park, trips out and about. V sturdy wheels. For central London not so great to be honest, you really have to plan your journey. My gap ended up being quite big so we only used it a handful of times but it has been great for the side carrier anyway for trips out. I can pack everything underneath or into the side carrier and be more hands free so to speak. Once my little one is closer to 18mths/2yrs I'll probably down size to a single fold one.
if you aren’t sure if you’re going to use it long etc I recently found out you could rent baby things! who knew!! I rented a buggy from Baboodle, really good service and they have a double buggy on there ☺️