This is fascinating. My history teacher at school was a vocal member of the Richard III Society. I wonder if any of the Royal Family will go to the re-interment? I wonder if the Queen gets to decide what happens.
York, I think, on the basis that most of its fabric was contemporary with him and is not a Victorian bodge-job.
Saltire George II was the last monarch to be buried in Westminster Abbey - there is no more room for royal burials. They have been buried at St George's Windsor, except for Victoria and her mad mausoleum at Frogmore.
My guess is that they will skip over the awkward fact of the Reformation by just doing reburial prayers and not a full on funeral. It's not as though the contemporary RCC would have been recognisable to him anyway.
Oooh! New thought! They could use the York Missal that was used in the North before Henry VIII - how super awesome would that be!