I've now switched to using silicone tube for siphon jobs as I can put those in the oven to sterilize them.
As for the draft lines, I'm not sure that they need replacing if you take care of them. At that point the beer is pretty resistant to infection due to the alcohol, CO2 and temperature. I think if you have got an infection in your kegging system you should replace all transfer tubing (which I am in the process of doing) but otherwise I don't think you need to replace it.
"People should not be afraid of their governments. Governments should be afraid of their people." - V
Secondary: Shady Lord RIS, Water to Barleywine, Pumpkin wine, burnt mead
Kegged: Crappy infected mild
Bottles: Apfelwein, 999 Barleywine, Oatmeal Stout, Robust Porter, Robust smoked porter, Simcoe Smash