Level Grinding Before Wallace In ORAS

I was wondering if anyone knew what place would be most efficient in grinding levels for pokemon levels 40+, before facing Wallace in Sootopolis City for the 8th Gym Badge.


The food court will give you some good trainers. However, if you have access to online, you can get usually get some pretty decent trainers and exp by fighting trainers in their Secret Bases after you "pass" them online.