Dodge Caravan Brakes

:evil:
I have taken my 1996 dodge caravan le to midas to have the brakes repaired five times in the last two years. I live in a small town, where speed is not necessary. On the latest trip to midas my brake pedal was going completely to the floor and had to pump the brakes to stop. Well midas was unable to check my master cylinder so I took it elsewhere and had the master cylinder replaced. Seemed to do o.K. With the exception of the warped rotors. About one week went by of not driving the vehicle and I got no further than the end of the block when my pedal seemed to go to the floor and stopping distance was about 500 feet! What is going on? I have an appointment with midas once again next friday to install factory pads. Will this help? Is there a difference between semi-metallic, ceramic, or factory pads? Which is best for the caravan? Are you not suppose to be able to stop on a dime in the likely event that some little kid runs in front of my van? Or am I suppose to ride around with one foot on the gas and the other on the brake. And just to clear my mind, midas sucks hard!