Having had a mild whiplash due to being in an auto accident I stay away from headstands. I do enjoy my husband's inversion table and I also have a headstand "stool" I purchased which allows my weight to be on my shoulders as I invert into headstand rather than my neck. Both of these allow me to enjoy inverting without compromise to my neck.
I always do shoulder stand with a folded blanket under my shoulders and arms (but not my head)so that my head is an inch or two lower than my arms. It takes a large amount of pressure off of the cervical spine area at the back of the neck and also makes it easier to breath.