I've looked at some R//C engine silicon fuel line. Its very soft. It's rated for some pretty volatile fuels, like nitrous. Depending on which you choose, some have 400F/200C temp range. Cold end as well, like -112F. Just about right for around here. crap I hate winter.... Like this stuff: http://www.coleparmer.ca/Product/Tygon_Silicone_Tubing_1_16_ID_x_3_16_OD_50_ft_pack/RK-95702-02 At the very least, why not hook up what fuel line you choose in nice loop or coil rather than insisting on making that 180 bend and being bothered by kinking and hardening? Just rambling..