Beekissed
Mountain Sage
Your cats don't go after the chicks? That has mainly kept me from adding any cats here.
I've never had any problem with my cats around my chicks. They just ignore them. One time I had a few really young cats that I showed chicks to and one started to crouch and do the tail twitch. I corrected him verbally and gave him a light tap on the head to snap him out of it and that never happened again. Much like dogs, if your cats respect you, they usually won't touch what is "yours".
Broody mamas also help with that....my broodies are dragon broodies, so any cat coming near their babies is going to get a face full of claws and beak real quick and in a hurry.