To lengthen the brake cables,you could try flipping them side-to-side,mount the levers over the axle,instead of under.Also cut off the cable-bracket,relocate it,then make a new rod,or extend it from the pedal to cables.You can also get WorkHorse cables,they are longer.You will need to weld your shackles to the swing-arm so that they only pivot in one direction,otherwise they will let the axle sway.Looking good!Hope this helps.