What lift ya going with? Depending on the lift, you probably wont need extended lines! I am up 3" in front and soon to be between 3.5"-4.5" or so in the rear and wont need to replace lines according to Greg @ PRG!!!
the rear shock is the limiting factor, if you're keeping the stock shocks you don't need new brake lines....
with my deavers and shackles (and new shocks) at full droop in the rear the lines are fully extended and stressed.....if you are putting on longer travel shocks you will need new lines in the event of full extension.
btw, i picked some stainless steel ones from AC, but i've seen them cheaper not stainless.