If you like the size of the standard duna multy but want a barred cage, I really liked the Skyline Ted - I got it as a holiday cage for our Syrian and it's really nice - not too big, not too small, has 7mm bar spacing and a good house built in. Access isn't great with just two small doors on top but I found it find for putting food and water in and the bar top is easy enough to just lift off.
https://www.amazon.co.uk/d/50t/Skyli...ds=Skyline+Ted
Personally I think it's a bit on the small side for a robo, but it depends on the hamster.
There's also the Liberta Varazze cage. Front door and top door, 6 to 7mm bar spacing - and 70cm by 40cm - it's a bit taller than the others though so would need shelves and setting up to avoid fall risks (the one it comes with are a bit flimsy apparently)
Liberta Riviera Varazze Large Mouse Hamster Cage