I used 380 motors to drive the 12 pound bot Scurrie around. 25:1 on 3" wheels at 6.6v. It was slow but I never replaced one. I think you could go 3S lipo and the ~14:1 boxes shown here in a mantis for sure. Going by the specs on the banebots site you won't be able to use more than 2" or so wheels in a 10' box without wasting it. That puts your right around 11 mph which is pretty zippy in that space I think.
The traxxas motor would likely be more powerful, but they don't post real specs so it's tough to say. Long can 400's add just a little bit of weight and size, but bolt up the same as 380 motors and can handle more voltage. If you went to 4S and 3" wheels you could get 12.4 MPH out of that same ~10 feet. Not sure the added weight, space, and cost of that system is worth it, but if your design calls for the bigger wheels it might be a good bet.
Thanks for checking these out Kyle
edit: removed rogue "long can 400s"
-Zac