Im thinking something in the 1600kv range would be best for 6s lipo and those very reasonable top speeds of around 45mph you are after. My first choice would be that 1521 1y for sure, 2nd option would be an 80mm Medusa in 1600kv flavour (cheaper, great quality, just not quite as powerful).
i think it was around 12lbs if im right, im pretty hooked on neu motors as i love my other one 1515 1y, but figured i can trade it off plus some cash for a 1521 1y, after further reading here am i going to have problems running my mmmv3 with 6s and this motor?
Losi Muggy
medusa 36-80-2000kv
6s turnigy 30c
MMMV3
46ts/ 14-16p
spektrum radio