There is a user of the forum that certainly qualify as a good instructor. I read he reached 99% on the April exam, he could be lying, but I think not. His name is Bill Shillito, his resume says that he tutors for the Gre Math. http://www.solidangl.es/p/resume.html
He also published a nice series of videos on youtube (link
There is also Charles Rambo, http://www.rambotutoring.com/
. His website has solutions to 3 past GRE exams.
But I think neither of them is in your area
If you are willing to spend some money on your preparation, I believe the only thing you could do, besides studying, would be to take as many exams as you can. Consider the April and September exams as expensive mock tests for doing better on October