hi ppl,could any one please tell me what hop up battery pack to get for my vrx 2.ive just put in 2 high torque servos and want to know what i can put in.i have 4 standard aa 1.5 pack so i take it that its running at 6 volts?would i be better to use 11 volt pach and what Mah do i go for?i have traxxas 2055 and hitech hs645MG.can any one help please?