In need of advice regarding gearing

[mothman]

Im working on a BL Savage project. Planning to run this truck with 7XL and 5s Lipo. I havent decided on the controller yet. But I've short listed 2 controllers so far, MGM160 and warrior 9920. Im working on the motor mount right now. So i need to order 7xl in order to make sure that the measurement of the motor mount are accurate. Since im going to order the 7xl from Mike, i'm going to order all of the stuffs (pinion, spur, motor, controller etc) that i need for this project from him at once.

So i need some advice on the gearing option( pinion and spur) for my savage. Im not looking for speed, 35-40mph is more than enough for me. Im looking for run time and i dont want to fry the controllers if i gear it too high or too low. FYI im going to use savage GT Tires, 6"x3.15" (since the gearing depends on the diameter of the tires).

My second question is, which controller I should get? the MGM 160 or the warrior 9920. Since i cant use the mechanical brake if i convert the savage to BL, Im going to rely on the controller for the brake. So I need a controller that can take a bit more punishment.

So i really hope you guys can shed some light. I'm going to order all of the stuffs from Mike in 2-3 days time (except for the 9920 if i decided on that one)

All help, advice and comments are greatly appreciated.

Thanks