What sort of joint custody arrangements could my ex and I come up with if I move to a different state?

First of course you will have to get the court to allow you to move if your ex does not want the child moved out of state.

But it would have to be an agreeable one, what has your ex suggested?

There are a variety of options. Alternate holidays, summers, etc.

what sort of joint custody arrangements could my ex and I come up with if I move to a different state?
Well I see life like this you and your ex have kids and the kids love both of there parent so why both parent can just for get this custody arrangement and let the kids see the other parent when ever they can. Never keep the kids from the other parent all ways have the kids in mind not how you are feeling about the other person get over it and just live your life and be happy and make sure that every one else as far as the kids are happy seeing the other parent