Linear actuator and controller

Quick question here.

I am planning to get a linear actuator and want to be able to control the speed with an arduino. I take it from what I've seen that an actuator just uses a dc motor (such as this one for example:

--So if I buy a dc motor controller and use it with arduino I should be able to adjust the delay in some code and adjust the speed right?

The controller I will use will most likely be this one:

or this one:

or this one:

--Out of those controllers which would be best to go with based on what I've said above, all the controllers are within my voltage ad current range for the actuators I'm looking at.

--One other thing- Should I go with a 12V and max 6.5 amp actuator or 24v and 3 amp actuator. Does it really matter which I get? Or does the different voltage and amp combo make a difference to force the actuator can apply? Sellers usually offer those 2 options!

Thankyou in advance

You need to choose the actuator based on the performance you want from it, in terms of force and speed. if you don't know what performance you need its going to be hard to know which one is going to work for you.

Make sure the actuator can provide a healthy margin of force for your needs, and realise the speed quoted will be a no-load speed, expect slowdown under load.