I am certainly no expert on brakes but I understand that increasing the braking at the front (via better calipers, softer/higher friction pads, and/or larger rotors) would increase the front/rear bias problem that you and most of us with Harrison's face. The fitting of higher friction pads at the rear helped a lot in my case for little cost (I got mine from Pedders), as they did for some others.
The key issue is the 'crack point", where the fronts are supposed to lock (on non-ABS systems) before the rears - just. You don't want the rear end coming around to meet you. For QT inspection they will (separately) test the rear braking on their roller. You need to have enough there to pass their test but not so much that they lock first.
See:
http://autospeed.co.nz/cms/title_Bra...1/article.html
I believe that this is similar to the PBR MC that you will have:
