Brushless power

hey guys, ive just purchaced the front and rear end of a revo to go with the G2R chassis when it arrives. Im having alot of trouble with my emaxx constantly having to upgrade parts to make it strong so it will take the power...will the G2R be the same? What have people broken on them? What is an essential upgrade? what brushless combo would be best for at least 5-10 minute runtimes on 14 cells but would like the option to go up to around 16-18? Ive been told the 9920, 7xl/10xl are a good combo?? How would they be geared/ Is Mod 1 worth it for the revo?

sorry about all the questions, just dont want to make anymore wrong desicions. Thanks in advance.

Cheers Adam