Hi. Hard to say what is a step up sine we don't know what Kiwi's in now......
However, the 1st cage, being 33" x 22" or something like that is, in my opinion, a very nice size for a "small" cage. I confess I am firmly tied to the idea of getting the biggest cage you possibly can. Personally, I would walk into that seed gaurd and tear open my leg, but maybe you are more sophisticated.
This is the cage I use.
http://www.birdscomfort.com/doubleflight_bird_cage.html
This is the cage I would rather use.
http://www.birdscomfort.com/double_bird_cages.html
When you select your cage, pay attention to features that will make it easy or hard to maintain, such as size of doors, locks, ease of sliding the pan, where to put your supplemental light, etc.
-MissK