you need bigger calipers. I put brembo vented disks on my k10 with mintex pads and K!1 march calipers. They work a lot beter than the old ones did, but to be fair - we noticed a master cylinder fault when bleeding the system so changed that, which may have helped, but the old disks were shot.
On a note of vented disks - they is no gain to be had in everday driving. The only benefit they have is better cooling if they are hammered.
New standard disks and good pads will be just as effective to the average.
I only put them on mine because i had a set lying around.