RE: Newbe at 3d electric flyiing
Outrunners have the outer casing that rotates, therefore producing more torque, eliminating the need for a gearbox, which can be noisy and adds weight. Inrunners have higher rpms, and lower torque, therefore making it so that you need to run a gearbox, or use the motor in a faster plane. Inrunners are more for sporty or high speed planes, whereas outrunners are for generally anything that requires a big prop.
IMO, any 12-16oz. foamy is perfect for your lipos.