Hi 172, welome to Sierra Golf!
Agree completely with IanR, and I would worry that unless you chose an instructor from the UK, they wouldn't even realise the sort of support and practice you'd be looking for. When a friend of mind retired to Spain, she asked me to come out with her so that she could practice driving on the right without her husband watching over her. It worked for her and something similar is possibly all that you'll need, although I don't know your circumstances. There are many kind people on SG who would come out with you if you should want them too.
Good luck and well done with buying on SG.