Right I think I've murdered my brakes. I get huge amounts of vibration under braking and it feels like the steering wheel is gonna jump from my hands.

I'm currently running a Focus ST170 conversion on the front and standard rear drums on the back (been on for 9 years). I'm seriously considering getting shot of the drums as power is at 250bhp and I wanna know it will stop when I press the middle pedal. What can I do with my ST170 conversion to improve it and is it worth fitting discs on the back. I don't mind spending a few quid (to a point) but don't want the wobble to return after 2 months of use.