I'm running 12 feet of 1/2" stainless-braided stainless (the moderately flexible, ribbed stainless, exhaust-hose-esque stuff), 6 feet of 1/2" stainless-braided Teflon, and another 12 feet of 3/8" FLEXTRAL hydraulic tubing.
The 1/2" stainless stuff was all laying in the garage along with another 15 foot of the stainless-on-stainless that I used for a transmission line... The FLEXTRAL stuff is bulletproof to 3000 PSI and was dirt cheap. And I'm almost sure that it's all rated for Diesel fuel too.