Northern Tool has the fittings and lines, look around in their big catalog to familiarize your self with the ends needed.
I had my lines made by lubrimation in Charlotte because I stepped up to a higher pressure rated hose.
You'll need a pipe tap to do your box and a "bottoming" tap also (or just cut some off of the first tap) to get a deeper bite.
I have less than $100 in my hydro assist set up and most of the money was the 8" 3500 psi cylinder.