I dont know what 1/8 your referring too with 2 motors, but you battery wont drain twice as fast with 2 motors. I could see it doing it with a NiMH battery, but if you went to a Lipo, your batteries last probably close to 1-2 hours depending on how you use your rig.
I had many many many RC crawlers, and my favorite had tt bed the Enroute Bergs. LOTS of fun, but also very spendy. I competed with mine, so the berg was probably the best for comps. Now it is probably a toss-up between the bergs, and the new Axial XR10.