We are visiting our friends in the US on vacations and would like to get married while there, but neither of us are citizens of the US.

Which states allowing same sex marriage in the US for two foreigners on vacation? I found lots of states which allows same-sex marriage for the US citizens, including: Massachusetts, Connecticut, Iowa, Vermont, New Hampshire, Washington D.C., New York, Washington, Maine, Maryland, California, Delaware, Minnesota, Rhode Island, New Jersey, Hawaii, New Mexico, Oregon, Pennsylvania, Illinois. But it is unclear is it possible to do get married in case we are both non-citizens (citizens for some other country, not the US)?

How long should it take (in each state) to do that (if there any waiting period between applying for marriage license)? For example Illinois has mandatory one-day waiting period for same-sex couples able to apply for marriage licenses.

How much it'll cost (in each state) and which countries will recognize it abroad?

How to contact a government of a state to find out all the details and to receive "official statement" on the subject?

The same question regarding the UK here.