at advance we sell poly-vinyl-fluorine coated lines for a few bucks a piece. you CAN go with some rubber FI hose for about $1.50 a foot or some PVF coated hard line for about $2.00 a foot. comes in 2-6 foot pre-flared sections with fittings attached, or in 25 foot rolls and you put your on own fittings and flare it yourself as well.
the biggest downside to having hard line, is if you need to add/splice anything, it's not as easy as with rubber hose.
i will be using hard line myself.
do you think it would be wise to use never seize on the fittings, or would just some good ol' teflon tape be the best answer?