Both are wrong for gays. Noone has given a sufficient explanation of what the compelling interest of the state is in any form of homosexual unions. This goes triple if the word marriage is used, and double if civil union is defined to be equivalent legally to marriage.
Many valid points have been raised about folks who are not man and wife raising children. All of these points apply as well to gay couples as to any other (non-traditional) configuration of persons raising a child. We probably need to create some social contract law that brings order to the situations arising for all of these people. That should take care of all the legal issues.
Clearly there is no reason for me to object to having some sort of registry for gay couples. But equally clearly that is not what the activists want. They want legal benefits, the whole shebang.