Rather than the Zoozone 1, you could look at the duna multy - it's virtually identical but doesn't need meshing as the bar spacing on top is smaller, and it's a good price here. Their delivery is quick too. It comes in various colours - you don't know which till it arrives I think.
Cage Duna Multy
The maxi duna multy mentioned is also excellent, but costs a lot more (about £80) - also on Porton aquapet. For that size it's a lot cheaper to get the Zoozone 2 (£50 ish) and mesh the lid, but the lid is better on the maxi duna multy.
It's a tricky one. If you get the standard duna multy or medium Zoozone, you might need to upgrade later, spending more. But some dwarf hamster owners find the hamsters prefer smaller cages. You could get the bigger one and fill a third of it at one end with bedding to make it smaller inside to start with, so you can expand into it, rather than getting a smaller one and then having to buy another cage later. A bigger one does give you more scope for making it interesting with lots of toys and tubes and hideouts.
Another option is a bin cage, which works out quite cheap, but you need to do a bit of diy, cutting holes in the bin and meshing them. The £10 78cm Ikea Samla bin is popular.
Or some dwarf hamster owners prefer cages. I think you'd do fine with a standard duna multy - it's a good size - and then see if an upgrade is needed later. If so you could always sell the standard duna multy again.