[Tom Line]

Think along different lines. You already got your answer on how fast the cylinders can go (and here's a hint - you don't have the volume or the flow rate to get anywhere near that....).

So now you need to look at how much flow rate you DO have, how much pressure and volume you DO have, and you can turn a shorter stroke into a longer one.

Hint 1: Mechanical Advantage.
Hint 2: Think lever arm.