I use the breakaway collars for all of mine. I like the breakaway ones because if they get caught on something they will come apart and not strangle them.

I use lucky pet for their ID's http://www.luckypet.com/ they have a good selection and good prices. I also like to get with my order (for just a couple dollars more) the pet safety reflectors that go on doors or windows in case of fire....they alert the fire fighters that there are animals inside the house or apartment.