Unless wanting to work, in preference I would recommend a non-O visa based on retirement as it is a lot less hassle to extend annually than the marriage visa.
Emirates are the pits. They used to be good but now they dont seem to give a shit about their passengers. They changed my return flight but didnt show the extra stopover at Phuket in the new itinerary. 2 boring hours sitting there in the middle of the night and 2 more hours before I could get some sleep! Not even an apology!
A personal friend obtained an OA from London with Nationwide travel insurance 2 years ago when they were at their strictest. I used the same to get a 90 day O visa.