Hi there, I m new to the drones hobby. I want to know which mini drone has brushless motors and altitude hold function. Camera is not mandatory. My purpose is indoor flying with kids with suitable battery time or if possible with replaceable batteries. Customs have issue in my country so I can't buy a large drone. S9hw, E012HC etc. JJRC H36 sizes are what I cam buy. My main source of buying is ordering online from China. Please help out.