Where's teh best location/ best trainer to rebattle for attack ev-training?
Thanks again d00dz.
A great place to EV train for Attack is in Route 212. In Route 212, there is both Kricketune and Bibarel which is useful as they both help you in Attack by 2 points. Another place to EV train in Attack would be in Route 202 where you can get 1 EV from Shinx. I'd recommend EV training in Attack in Route 212 as you'd get more EV's from Bibarel and Kricketune.
In my opinion, it's best to EV train in the grass instead of trainers as sometimes they wouldn't want to re-battle you again after you use the VS Seeker many times.
Though for the pokémon in the grass that will raise your EV's in attack, you could always use the poké radar so you wouldn't have a hard time finding them after one battle with them.