I used 1/2" hardware cloth for it all, but I know that it may be a fault in judgement when the breeders all go to tubs! Oh well, we'll cross that bridge if it comes.
I buy hardware cloth from Tractor supply. I'd use 1/2" for the food hoppers, and 1/4" for the tops.
I'll get a better pic tonight of what I did... Gots to go home now!