Why do you need bigger brakes? total waste of money unless your doing serious track days. Even Cup racers use standard discs.
It is really annoying when people say this, just because the cup race car used standard discs doesnt mean thats the best set up, they used PF97 pads, which is like sticking a bar in ur wheels and coming to a stop and they did a what 15 lap race with proper brake cooling.
They also used parts that would keep the cost down for teams, a 60 quid pair of discs and 100 set of pads is a lot cheaper than replacing the discs on a 4 pot set up.
Doing a full day on track your going to see the benefits of 4 pots easily.
Back to discs - these look good -
http://www.k-tecracing.com/show_product.asp?id=2525
ds2500 pads are good so go for brake kit 3!