YOu can get one from your local auto parts store (pre flaired and with fittings installed) in many different lengths. You will just have to measure your good one (on the other side) and get the right length and fitting type and bend it to fit. I dunno where you can get a stock pre-bent hard line and if you go to a junk yard there prolly all rusted and on their way out anyways.
I assume your talking about the hard line as you say STEEL....if so, not really an upgrade for those. I suppose you can go to SS hard lines but thats very rare to see.