how do i fix a poor handbrake? peugeot 406 2.1td 1997?

I have an ongoing battle with a friends peug 406 saloon. Never been a pug fan, this is one of the reasons why!! Firstly the handbrake has never been of much use, have tried cleaning out the disc/drums + scuffing up with some emery, then carefully adjusting the shoes, the handbrake itself feels great, just doesnt hold the car. I have replaced the shoes recently, + made sure all cables/mechanisms opperate freely. Still no good. You could probably push the car on a flat road with h/brake on! Maybe i'll replace disc/drums next?? Any ideas before i burn it??!!