Just ran across this it may not be of any use to you anymore but it will cost you a lot you can figure about $3 per foot of hose I know the price of the hose is actually slightly less but by the time you put the fittings on it that's about where usually averages and that's getting quad braid hose you could go dual braid but for something that's keeping me in the air in my life kind of depends on it I'm getting the best available.
Yeah on the newer trucks there are for there was when it left the factory I seen two newer trucks that the safety valves were pulled out of the cylinder so the bucket would operate faster so after seeing that I just assumed that there's not a safety valve in there that way that way I'm more cautious and methodical in my maintenance inspections it's better to be safe than sorry and it's been my experience to never rely on any backup safety device no matter how good it is or what it is
They're called counter balance valves. Anything that lifts a person, has them directly on the cylinder, before any flexible lines. You can blow every hose off and not fall.
And if anyone ever bypassed, or removed them to "speed it up" they need a high five in the face with a shovel.