I could be wrong, I often am, but here is how I ran the hydraulic lines on my 5555 for my Wicked Grapple. First we used a retired team roping rope passing it through the tractor from the back to the front where we thought the hoses should go, marked a place on the rope about midway of the front cross brace on the FEL and pulled the rope out. Then stretched the rope straight and measured it. It was 21 feet and I added a foot just in case.
My local auto parts house makes hydraulic hoses. They get $.32 an inch for 1/4 inch ID, .34 for 3/8s and .39 for 1/2 inch. It was only $11 more to go with 3/8 and even though it is merely 50% larger in diameter it actually flows 2.25 times as much fluid which would make the lid a little snappier.
The Wicked Grapple comes with Pioneer style quick disconnects, one male and one female. This is pure genius. Every manufacturer of tractors and attachments should have one male and one female. The reason becomes obvious in the picture below. It allows the hose ends to be connected together when not attached to an implement, keeping them clean and avoiding problems if the operator grabs the wrong handle.
My auto parts man asked me if I wanted straight or 90 degree or some other angle fittings. To keep things neat and tidy out back, I went with 90s so that there would not be big honking 180 degree bends flopping around. The 90s also made it easier to take advantage of the male/female connectors up front.
For the time being, zip cords hold the hoses. After we get the grapple and settle on the final configuration, we will use screwed on clamps to secure the lines. It looks like 22 feet is going to be too long, but that's better than too short.