All of those are good! i love number 4 i may by that to get another bird

...but yeah all those are good! i just dont reccomend the number 7 as the bars are just so flimsy. you wont be able to attach perches or heavy toys (like wood toys or ladders etc).you really need to be able to put in perches. i also dont reccomend using the perches cages come with as the only perch. they need different types and shapes of perches. if you use just the one it comes with they have a high risk of getting arthritus in there feet.my conure has 4 perches and my parrotlet has 4 perches as well.