Hmm... Personally, I wouldn't choose a rabbit cage for a hamster. Of course, you can mesh it to reduce bar spacing. I think the cages you chose would also need to be meshed on the sides, since the ventilation slits seem rather wide for a hamster. Generally though, I think this could make opening the cage, cleaning the cage and generally interacting with your pet a bit more difficult and resolve in a daily hassle.
Also, I would recommend a cage that allows you to watch and interact with your pet from different angles, especially if you want to stack them on top of each other. My hamster finds it a little bit scary, when I put my hand in from the top of cage. But when I use one of the side doors, he is much calmer.
And I agree with the others, the cage and the mesh (and maybe some tools for the meshing) won't necessarily save you any money. A more hamster appropriate cage might cost you a little more but it would be a great investment in your pet.
If you need your cage a.s.a.p. I would definitely choose the Barney cage from zooplus. If you can wait a little bit longer and save some money for it, I would go for a cage with a clear (acrylic) glass base, like the Ferplast Karat, the Falco or the San Marino (that's the one I have and I love it! <3 ). It's so cute to watch your hamster digging its tunnels in the substrate, for me that's really worth the higher price! (Of course you could always opt for a regular glass tank and add a DIY meshed top. But these are not stackable.)