soft brake pedal

that doesn't make sense but may be correct
Are your ssbc 4 piston calipers floating,the kelsey hayes are fixed so all 4 pistons move the same amount

Fixed. They are copies of the originals, just in aluminum. Again, not sure why the piston area is calculated that way. Read about it here.

The only other thing I would suggest before you start throwing parts at the problem is to verify how much pressure you have at the wheels. There is an inexpensive pressure gauge kit to do this. Click here.