first off yes i do use a vacuum pump......to elaborate on your car.
a power booster will not operate properly on 11-12 in of vacuum i dont
car what calipers or pads you use. your brake will feel hard as hell and if
you weigh less than 650lbs you wont be able to stop very well.
get a vacuum pump!!!!!!
you will find your face will hit the steering wheel with all the stopping power
you will have. there are plenty of brake tech sites out there to support
what im posting, i have 10 in of vacuum without pump, brakes sucked.
i installed this pump....
http://www.metricmind.com/pump.htm
the top one pictured,
costs more than the belt driven ones, but designed for an electric vehicle
that generates no vacuum, so it can be run in line without a vacuum canister
i love it.