I've had good luck with the yellow oregon brand tygon type line. They reformulated somewhat recently and its said to tolerate up to 25% ehtanol now. I've used this line for several years and still have some that's pliable from 5-6 years ago. I've only seen it in yellow though. I get mine from a small engine shop by my house. Its sold as fuel line for weed eaters, chain saws, etc. It can be a bit pricey but you get what you pay for.