Toss the inheritance tax - a/k/a stealing money given from one family member to another - and let people establish private interpersonal contracts which are valid only between the signers.
The peril of civil unions is that forced recognition / subsidizing of them falls on everyone else.
And the income code tax too. Ever filed Married Single vs Married Joint?
Just do a flat tax and no inheritance tax, there is nothing but ego and political posturing that pushes for Gay Marriage.
It's more about the money than anything else.