Yes, it's best to replace the entire line, from the distribution block to each caliper. I've done them. For the longest time I used to avoid brake lines because I thought they were difficult, but they're really not. Annoying more than anything but by no means difficult. Even on your back on axle stands, you can do a nice job.
As far as I know you won't be able to find premade lines. You have to make them.
You're going to need a roll of 3/16 brake line, as well as 3/16 (M10x1.0) flare nuts for each end. My suggestion is get the EZ Bend tubing, you can bend that nicely with your hands. Standard brake tubing will require a tube bender for the nicest and best results.
Trick is to use a GOOD flaring tool. Don't buy the $30 because it will flare like crap. I tried. Gave up and rented the tool from Parts Source, and all my flares came out perfect and no leaks.
You'll also need a tube cutter, a file, and some brake fluid (of course). Tube cutter cuts nice and smooth. A trick with the file is to get rid of any burrs the cutter may have left, and it helps to put a slight 45 degree taper on the end of the line you're about to flare. This is also where a little bit of brake fluid comes in handy. You use it as a lubricant for the flaring tool/brake line while you're flaring. You can't use motor oil or WD40 as you don't want any of these contaminating the brake fluid once the job is done. Use brake fluid from the get-go, just wear gloves and make sure you don't spill any on paint
