i have watched many a video of weaned kits and small chins escaping from 1x1 inch bar spacing. you definitely want the hardware cloth.
home depot carries stainless steel wire on a small roll and it is cheap, just a few bucks at most (i recall my roll for toy making being 1.99 or something like that).
wrap the hardware cloth inside the cage, not outside. this will prevent chins from getting stuck between the hardware cloth and the cage bars.