I was able to defeat kanto with a level 92 blastoise and 95 alakazam. The remaining fillers were a level 82 raichu, 84 steelix, blah blah blah.. All that matters is that you want a strong and reliable team. And make sure you bring plenty of potions, revives, and full heals.
Great newbie informer here.
But I wouldn't call this a "guide".