By popular request, I've gotten a supply of bladder tubing more suitable for F2D.  It has a thicker wall than the Yellowjacket tubing and is solid black.  The thicker wall holds up better in F2D ships, which usually use a larger diameter bladder compartment that doesn't support the bladder.  $18/5 ft.

The fuel line is black surgical tubing(very soft) with a 1/16 in. ID and a heavy wall.  Very easy to pinch, either by hand or with a shutoff.  Since it's latex, it probably won't hold up quite as well as neoprene but it stays on the nva nicely. $13/5ft.

A tip about bladders, get more life out of one by making sure to empty it out completely after every flight, and keep it cool(in your pocket) in between flights.  Leaving a bladder with fuel in it in a plane in the sun is a sure way to make it go soft prematurely.