The battery area is big enough to hold a 6 cell 2/3A typical mini stick pack. Take that size to Lipo and you can fit up to about 1250mah and 2 cells or about 800mah and 3 cells. Motor-wise the mounting plate cannot have the bearing sticking out...it must be flat. The can length can be up to 35mm long, any longer and it touches the body work. Use a 2.3mm shaft as well. Most bolt patterns will work and the screw size can be 2.5mm and 3mm, both will work. For KV in the brushless motor I dont suggest any more than 6500kv, makes it harder to control and the bottom end is less forgiving if your not careful and tune for it.