You say want to do it correctly the first time-your off to a good start.
In my case I used four sets of hoses to do that on my NH TC40S.
Two hoses from the rear remotes to the FEL dock starting with a set of male QCs at the rear female remotes and ending with a set of crimped 90 degree bent tubes that attach to a set of bulkhead unions. You need to build a bracket for the bulkhead unions.
Two hoses from the FEL dock to the edge of the FEL torque tube starting with two sets of 1/2" male/female QCs threaded onto the bulkhead unions, a couple of double hose brackets along the FEL arm run and ending with a set of crimped 90 degree bent tubes onto a set of bulkhead unions. You need to build a bracket for the bulkhead unions.
Two hoses from the edge of the FEL torque tube to the center or vicinity of the torque tube starting with a set of crimped straight fittings onto the set of bulkhead unions and ending with a set of crimped swivel fittings onto a set of 90 degree fittings attachet to a set of bulkhead unions. You need to build a bracket for the bulkhead unions.
Two hoses from the center or vicinity of the FEL torque tube to the
grapple cylinder starting with two sets of 1/2" male/female QCs threaded onto the bulkhead union and ending with a set of crimped fittings compatible with your
grapple cylinder.
I used 1/2" Pioneer QCs adapted to 3/8" hoses as the 3/8" routs a lot easier than 1/2" hose.
Use a charged air hose if you have one as a measurement tool for your hydraulic hose lengths. When measuring the hoses from the FEL dock to the edge of the FEL torque tube, look at how your tractor's manufacturer created the "S" configuration in the hoses that power the FEL bucket. That is at least how much slack you will also need in them when you raise the FEL.
Don't make up the last set of hoses to the
grapple until you have the
grapple installed as there is no way beforehand to tell how much slack will be required.
I used the left side FEL arm to run the hoses as the right side was way too cluttered with factory pipes and hoses.
There are several hydraulic shops in my (ag) area and picked the one that felt comfortable-happened to be the closest to me.
I made A LOT of trips back and fourth to the hydraulic shop starting from the back of the tractor with first set of hose measurements with an extra foot or so tacked on and had only the upstream end crimped, went home, attached, detached and back to the hydraulic shop for the final cut to length and other end crimping.
I went into this project as a complete flaming no-nothing hydraulic sub-novice but just put forth ideas what I wanted to wind up with and in most cases the Hydraulic shop guys built it with their expert parts knowledge to my plan. Some will say what I did was a bit of over-build but if you look at various factory installs you will see the same sort of applications that I chose. Apologies in advance to those who have already seen the photos. Have at it at any level you wish but go into it with the notion of only having to buy it and build it once. Good luck.