A bare 200mW 5.8gHz transmitter module uses 340mA max at 3.3v. A camera should be less than 500mW for a small FPV model and foxtech has some that will run at 3.3V like the transmitter module. Use a $30 camera and a 20 dollar transmitter module like this but build a skew planar for it. Run it from a 3.3V BEC.
Thurmond
Thurmond