My understanding of the R33 brakes Vs the VT brakes is that the VT ones are not too much for the R33 ones, but the bias is just off. So, using a balance bar (as I understand it) would essentially mean that the rears come on stronger, and would not affect the stopping power of the fronts at all.
This site seems to explain it ok
Performance Friction Brakes
I'm thinking this may be a better way to go for my needs, as I don't require massive racing brakes - just a safe and reliable way to stop lol
:Edit - I think I may need to have a chat to a brakes specialist. Have spoken briefly to one brakes supplier for hotrods, who seems to think the calipers should work together ok if set up right. But as he said, he's hasn't seen the car or looked into it much.