going brushless w/ lipo would "save" a lot of weight in the front over the big can, and with the battery and esc right behind the motor you might even have to move the servos and reciever forward to compensate for the weight loss in the nose and I'd bet you'd still come out with less weight with more power and more mAh than using the can thus negating even the possibility of needing tail weight. Brushless is always better than cans, even if you somehow need to add dead weight to the nose. You will never need a brushless setup as heavy as a can to attain the same or even better power/weight ratio.