I fervently ask you to sign the civil marriage legislation, once it arrives on your desk.
Your recent statement says that the Federal law should be changed to extend rights. However, Federal law now relates to marriage, not to civil unions, and it is just as likely that Federal law will continue to do so.
You indicate that you are interested in equality, so you should be invested in ensuring that there is never any question about whether a legally-joined couple has the full equal rights and responsibilities of marriage. Civil unions leave that question open, both among New Hampshire citizens and when same-sex couples travel to other states.
If and when Federal law changes, you should not have left New Hampshire in a position of retrofitting our laws to meet Federal standards. Instead, by including same-sex couples in current state marriage law, you can leave New Hampshire prepared for any changes in Federal law.
The only way that you can ensure equality is to grant equality. If civil rights history & practice show anything, they indicate that separate is never equal. I urge you to bring to an end the exclusion of same-sex couples from civil marriage in the state of New Hampshire by signing the civil marriage legislation.