I know of a massive indoor equestrian center near folkestone (not the one we at DHD used) apparently one of europes largest
they approched my brother about using it so they are keen to have rc racing in there...had a bar and good canteen...great parking/camping...exactly what you are looking for Tony the owners were very helpfull and uber keen
they offered the venue to us for free
i can pm you the details if you like.....let me know.
cheers