I have found a vendor who will make you any length of Leader Hose. I had one made this morning that is 60" long. It is chaff resistant, oil and chemical resistant, and get this – will hold up to 4,000 psi.
This vendor is a local hardware store about 6 miles from my house. I never knew they made industrial pressure hoses and they have been doing it for decades. Here is their website:
http://www.clarksalesinc.com/clark-sales-hydraulic.html
There are pictures on my site of the hose I had made and a 24" Viair leader hose.
Good luck.
Bigdon68