I've had trouble with rats this year, digging under my big run on the ground to pull quail through the 13mm galvanised wire. They even tried chewing through it and broke a few threads before giving up! So mine are in elevated, stacked cages - much smaller than their old run but they seem happy enough.
Mine are solid wood other than the front which protects them from most of the elements as does the pohutukawa tree their cages are under. Think about what's a comfortable height for you to clean out because they are messy birds. I use straw as bedding as shavings get in their water and food every time they flap their wings.
It's best to keep a group that have been raised together, but you can still get the odd bird who likes to make trouble and pick on one of the others. They can be vicious if personalities clash. But once you have a happy group they are lovely birds. They can be very docile and friendly, especially if they are raised with lots of handling and exposure to people.
When were you planning on getting some? It's just we have Autumn around the corner (great to see another Kiwi on here) and they won't lay over winter without additional lighting. I like to give mine a winter break as otherwise they burn out faster. But our first females laid just as well in their third year as their first (before the rats got them

) despite being indoor birds for their first winter and laying all winter.
Anything else just ask!