See, the big problem with rods, mechanical linkages, and other cocammamie chain things, is that as the suspension flexes, the physical distances between brake pedal and brake itself changes. Basically the connection will be tightening and slackening as you travel over the terrain. Tightening will cause your brake to actuate itself. Not wanted. Slacking off will mean having to push the pedal further than you may anticipate, possibly not far enough with a pedal stop in place. So- insufficient/ no braking, and/or self-braking, all randomly changing moment by moment over the terrain. Sound like a good idea to you? Just use a good cable.
EDIT- Gokart, why don't you post up some pics of your setup? Perhaps that will help make things a little more clear. Also- What was used before, and why are you unwilling to track down a good cable?