It is really easy to upgrade the plastic lines, and here is the cheapest and easiest way to do that.
Get the Swagelok adapters Bill referred to:
Swagelok for the 5/16" tube adapter to -6AN is part # SS-500-6-6AN
Swagelok for the 3/8" tube adapter to -6AN is part # SS-600-6-6AN
Get these Russell adapters for the stock connections at the fuel rails:
3/8" adapter is Russell part # 799-640850 (Jegs.com)
5/16" adapter is Russell part # 799-640860 (Jegs.com)
Get 3 feet of braided hose for the feed, and 3 feet for the return with -6AN hose ends, or buy pre-built -6AN lines. You can piece these together for as little as $50. (Russell and NOS both have pre-built lines for a little more).
Go to the hardware store and get a mini pipe cutter - looks like this:
Cut the hard lines under the brake booster, and install the Swagelok fittings down there. Then just run the braided lines to the Russell connectors.
Total cost should be somewhere around $100 for everything.