co2 line? the shortest amount possible, probably 2 ft from the primary reg to the manifold and about 1.5 ft from each valve to keg. why? building a kegerator?
Remember... hose capable of containing 10-15 psi or so is cheap... true "high pressure" hose is not. Unless you need full tank pressure in your keezer or storage container, install a regulator on the tank to drop the outlet pressure to around 10-12 psi (as long as it's still as high or higher than your highest storage or serving pressure), and run with that.
$0.53/ft..... good for under 20 psi or so.
$37.75 for what looks to be about 4-5 foot of hose.... good for full tank pressure.