uprating brakes

[Gabbo]

been to oulton park on saturday, had a good few runs out but after 3-4 laps as i broke from the straights my brakes judder like mad, thinkin of upgrading to grooved discs and some performance pads.
can any one help me out as to where to get some from, or what to get??
its a nova with a 2.0 8v in, the brakes are off the astra it came out of.

cheers guys :)

[Welsh Dan]

You can get them from tweeks, ebay, tuning.co.uk, rally design and allsorts of places. What is your budget?

[let_nova]

black diamond drilled and grooved disks. even gen vaux disks and pads are good.

[Gabbo]

not sure really what do they varey from and to??