For fuel line, 5/16 should be enough to keep a supply of fuel unless your running massive cubes. For the brake lines, you want to secure these so that they dont move. Remember, bending causes metal fatigue. As for drilling holes into your frame, there should be some already in place. If there isnt, you can drill small holes, but make them few and far between. Go for the center of the side, and i would reccomend self tapping metal screws. There are those who would dispute this, but it has always worked for me. As for connecting the line, if you buy in segments aka 10foot lengths, you can always make couplers where the segments join together. Or, you can just buy a coil and run solid lines from your tank to your carb or fuel rail. As for brakes, remove a section of your current brake line and replace it with the same size. Hope this helps