What you want is facelift front rotors with ST185 celica twinpots for the front.
Be careful to check they are right as the 185's also come with Single piston calipers and larger disks.
You can fit these easily but require the disk to be changed to 4x100.
For the rear it's a bit trickier, I fitted facelift front rotors with late model SW20 calipers, these require a 6mm thick rotor behind the disk.
Brake master cylinder can be upsized to 1" bore from a **N130 Hilux.
Here's a link to lots of discussion and other upgrades you can consider:
http://www.toymods.net/forums/showthread.php?t=2221
You might need to sign up but it's a great source of information