The only thing that gives me concern with the setup that you are proposing is the current draw. That 1940/7 is going to draw a good bit of current as it is. Running that hot of a motor in a 10+ lb truck on what will be essentially be 3.5S lipo is going to draw a lot of current.

What controller are you going to be running? If you're going with the MM, just watch the temps.

On the upside, those packs are very nice. I experimented with a couple of them when my LHS first got them in. They have punch right up until they dump and they do indeed charge in 15 minutes, although that 15 minutes is for each pack. It will take you around 30 minutes to charge both packs.

A ThunderPower 1010C should be able to charge both packs in series in 15 minutes.