Deathofdave having done about a dozen pneumatic props this link is the best to describe the solenoid / cylinder options.

Single action cylinders are ok but I prefer double acting cylinders.
Single action cylinders require a 3-way cylinder minimum.

4-way, 4 or 5 port solenoids are the best for double acting cylinders.

Flow Controls & pressure controls – You will need individual pressure control valves for each prop and / or flow control valves.
The pressure control valve will allow you to adjust the amount of POWER going to each prop.
Flow control valves control the SPEED of the motion. Some valves have internal flow adjustments or you can buy screw in controls.

PVC and Bike Pumps may make ok cylinders but the legal liability if something breaks and pokes out a Tot’s eye is too high for my taste. Buy real cylinders from eBay usually around $0.50 per inch of travel.

Cylinder mounting fittings (Rod Clevis with Pin & Pivot Brackets) can be found at McMaster-Carr page 893 and are cheap.

Instant Tube Fittings and Tubing are great for flexible configurations. McMaster-Carr page 138.

Hope that helps some.

__________________
"To see them running from my yard screaming full of fright
puts a joy in my heart I only get on Halloween night. "

Doug B.