I think thats a good motor ( 1520 ), or the 1518 would be good too, right kind of kv range for 5 or 6s lipo and ~40mph topspeed.
Would it be possible to relocate the lipos inside the TVPS at all, or atleast in the center of the chassis either side- looks rather odd with the lipos right at the back, makes the truck more prone to wheelie and waste power.
I agree with moving the lipo's.I just have to drill some new holes.The reason I mounted them there for now is the holes were already there.Right now the truck is pretty tail heavy.