Brake are easy, just need to get the setup balanced correctly, 1" master cylinder, adjustable prop valve and bigger rears. I have AZC 12.2" on the front and 12" on the rear and I can outbrake most cars I meet.
Don't go with the silvermine kit, size is good but they mount the wrong way and handbrake cable doesn't work well from what I hear. If there is anther run on the below kit, go for that, that's my setup and I can't fault it, balances out the front setup perfectly and it has a strong parking brake.
http://forums.hybridz.org/topic/113199-yet-another-rear-drum-to-disk-conversion-option/