Re: legality of gretna green marriages
There are a number of places where legal requirements are minimal.
We used south africa, only legal requirements was us to provide copies of birth certs and passports with valid entry visa, our minister filled out all official government documentation and we had full rubber stamped marriage certificate 3 days after ceremony.
Quick and easy (and probably less expensive to travel to), Vegas, New York, British Virgin Islands (each island has different requirements).....
If you do some internet research you will find the places that suit you with the minimum requirements.