A much more economical solution would be to consider using inexpensive R/C servos. By attaching push rods to extension arms from a rotary servo you can get linear travel. Think how they make a rubber move in a linear manner + and - from a neutral position using a rotary servo in any R/C controlled airplane. You can probably buy 10 or more servos for the price of a single industrial type linear actuator. Servos are available in many sizes to handle just about any torque load, your small panels should not be a problem in that manner.
Lefty