Multi outputs - 2 servos, and 2 linear actuators

I'm new to the arduino system and am working on a project where I require the control of a tilt and pan servos, along with a two linear actuators in parallel (don't need independent control; 0 to full extension no need for displacements in between).

The voltage rating is 12V for linear actuators and 6V for servos, which, I know is higher that the regular output, therefore needing the motor shield. But how would I go about this connection? Can the Arduino shield handle that many outputs?

I apologize if the question is overly vague, I haven't finalized the parts im using but as of now I'm looking at:
Pan: SPG5485A-BM
Tilt: SPT400
Linear Actuator: 12V Servo control http://www.servocity.com/html/25_lbs__thrust_linear_actuator.html

I am continually doing research and sifting through the forums for info, any help is greatly appreciated even guidance in the right direction. Thank you.

Firstly you cannot run those linear actuators in parallel without good positional feedback or they
may fight each other (assuming they are moving the same load). Also we don't know the
stall current rating for them, but at 0.8A no-load they probably take 10A or more stall.

Do you need PWM control of the actuators?

I believe I don't need PWM, I need the actuators to simply go from fully retracted to fully extended, at
relatively the same speed. At first I was thinking of making a rack and pinion system with a servo that extends two bars out in opposite directions, but have opted for two linear actuators that move outwards. If the Arduino can manage it, I could run the linear actuators
independently.

Still not 100% clear.
Are these 2 linear motors running separately or are they alwyas running at the same time, in opposite directions ?
If you don't need PWM to control the linear motors, you'll need 4 pins to control them in case they are to be controlled separate.
And 2 in case they need to be running in parallel (one to switch the direction and 1 to switch the power to the motors).
You can then switch by relay (all DPDT).
You need PWM to control the servos.
This PWM is a software hack in the library as far as i understand, but i'd guess you have plenty of pins to control your motors, and don't need a motorshield.

I am making a "Portal" sentry gun/turret. There will be one servo for panning, one servo for tilting, and two linear actuators that push the airsoft cannons outward into the firing position and retract upon shut down. They will be running at the same time and will be doing the same movement (mirror about vertical axis). I hope this clarifies.

At this point I will connect everything independently and power externally from a battery rack.

And thank you for your insight, it was very helpful.

Let me know if you have any suggestions or improvements, I'm a structural engineer and am going off one electrical course and one programming course I took in my bachelor's.