I get mine from Napa Auto parts. And Delta Rubber off hwy 99 in Stockton, but they have a store in Sac. also. Large truck parts stores will have it too. Napa sells it in 3' lengths and has tripple ply reinforcement for sturdy connections. The hose from Delta has single ply for a softer more flexible joint and is lighter.
To keep it from slipping I use a small tubing cutter with the cutting edge ground flat to make grooves in the header/cannister.
For clamping I use string wrapped around the silicone a couple times and pulled tight, knotted and CA'ed. Works great and is as lite as it can get.