I wouldn't use a collar. I would use a harness. I like the choke free harness from Lil Sis here on YT. or the Buddy belt from Maximo. Both are really good harnesses. I don't put collars on my girls since I heard there was a connection to CT. I would contact one of the ladies above. Neither one of my girls needed to get used to a harness so I can't help you with that one.
. I will post a picture in a few.