Around that lvl, I autoed on warriors in japan.

If you sit near a spawn point, you should recover enough hp/sp as long as you fights the right set of them. (1st floor of golden temple only has sets of 2, so that's good)
The warriors in there use no attack skills, so you don't have to worry that. They're around lvls 50-53, so you should get fair exp.

Remember the rules of auto:
1. Always set auto leave, even if you think you won't need it.
2. After setting the remote, watch for 5-10 fights to see how you do.
3. Always have food, even if you think you won't need it.