Welcome to PF, Sam
You might have to be a bit more specific about your question. For one thing, you haven't mentioned the scale of this thing.
If I were to build one, on a table-top device, I'd go with 3cc units for the activators and a 50cc to pump them up. That's just me, though; I love overkill.
For bigger scale, I don't know. From experience having played with these things, I can say for certain that a 50cc used as an actuator can lift over 130 lbs.. (I know because I was the load.)