Good luck finding pre-fabbed lines. Summit sells your favorite line sizes (3/16, 1/4, 5/16, 3/8) in rolls of 25' for about 15-20 bucks and bags of tubing nuts to go with it for about $7/bag. Get a pipe cutter, a flaring tool and a tube bender and you will be all set. Biggest challenge is grinding the appropriate bevel on the ends of the tubes...I made a jig that is used with my bench grinder that works well.
