best hardware for outside aviary?

[aart]

either heavy duty metal zip ties, or some type of liquid nails?

Zip ties could work.....I wouldn't use any kind of 'glue'.
Is there a roof option for that system?

 

[RoyalChick]

ew... yeah i just noticed that the 1/4" is 23 gauge..... yeah def going with the 1/2".

Yup - that is the issue - 1/4" is only in thinner gauge wire - if you see it up close it is quite flimsy.