just a thought for you, maybe go to some local skid steer attachment places that sell these and have a look at what they have, as for size of bore on cylinder
or contact a good cylinder shop (or maybe even a good hose making shop)
and tell them what your trying to do, and ask them for recommendations on what all to get to set you up(even better if maybe you can bring it to them to see for them, measure an d get you all you will need!
and also make sure when you get hoses you get them long enough, seen some of these stiff arm hoes with too short of hoses and had them get damaged due to not being long enough(same with routing them, so they don't get damaged!
lastly, things can get pretty costly here fast, so keep that in mind as to what its worth in the end
very easy to sink more into something than its worth!
my last two hoses I just had made were almost $400 bucks alone and they were NOT very long, less than 30 inches!
so, add in two hoses, a cylinder, pins, and what no;ts, and you can have a bunch of cash into this thing fast
and I have seen them for sale like yours for about $700 bucks up my way used or like a grand new!
I bought one a few yrs back for less!
here are two I found quickly on Craigslist that have pic's that may help you, plus shows prices of new VS used
maybe not your exact make/model, but gives you some ideas I hope!
https://tricities.craigslist.org/grd/d/rogersville-backhoe-front-hoe-skid/7855331677.html
https://tricities.craigslist.org/fod/d/elizabethton-new-heavy-duty-skid-steer/7881409600.html