The government (States) should not recognize marriage of any kind. "Marriage" should remain a religious entity.
On the other hand, States should recognize "civil unions" which would be a legal contract between two individuals (humans age 18 and above) which would afford them all the rights and privileges that are currently seen in marriage.
The "civil union" would in no way be synonymus with love or sex, but would in essense be a business contract. The government is not in a position to authorize licenses of love and sex, but they are in the position to issue licenses to conduct business. Therefore, the union could be between man and woman, two men, two women, or even relatives if it suited the two individuals from a insurance/tax/property ownership point of view.
I agree with you completely. As is if you do all of the proper paperwork homosexual or straight, you can basically recieve all of the same benefits. Keep a copy of the paper work with you when you travel in case, heaven forbid, there was an accident and someone ended up hospitalized, it is the responsible move anyways.
The title of marriage though is a covenant between you and God. States gave the legal title marriage because, lets be honest, this country was founded on religion.