Try replacing the caliper slider pistons.
It won't get rid of all the vibration if the disks are too warped, but I did it on mine, and it reduced it a lot.
Best get new disks as well though, then you should be ok....if it is entirely the breaks.
A dodgy wheel bearing or worn suspension parts, could make the vibration worse than it would otherwise be.
If you can though, do as above, and get some 16v breaks. You may as well while you're at it!