Suggest you pick one in Europe while it's still easy to do :) I think most EU countries let you apply for full citizenship after being there a while (e.g. France lets you apply after 5 yrs, less if you're married to a French national).
While we're veering OT fast, I really can't see Scotland staying in the Union once Brexit is complete.
There's still going to be strong ties with England, given all the toing and froing over the centuries - so I'd expect it to be quite easy for someone English to stay in Scotland almost regardless of what deal is eventually cut with the rest of the EU.