I finally got my car streetable after swapping the engine, and everything worked great and 100% including the brakes. The next day the opportunity came up to grab GSX rotors and calipers, so I jumped on it, and spent 4 hours hammering away to get the old rusted OEM GST rotors off. I even replaced the whole wheel bearing in the passenger side to get it off. I threw on the GSX rotor and dual piston caliper, bled the lines, and drove home cause it started to get late out and I was doing it at my buddies house (note just the passenger side was done at this point). On the way home, i realized the brakes were very soft, but I could still stop if I wanted to. I figured it was just not being bled completely.

The next day I spent another 4 hours getting the drivers side replaced with the GSX upgrade. Now I decided I'd bleed the lines for good, so I had a friend hit the pedal 10 times on both the drivers side and the passenger side to make sure there is no chance for air to be in line. Only now, there were no brakes at all on the car. And when I pump the brakes the A/FR jumps to about 18, then quickly comes back down to about 14 and would level at 13.7.

I figured I'd try swapping the brake booster over incase mine went bad, only that didn't do anything. I bled the master cylinder in the car (Opened the valve, had someone hit the brake, then close it, and let the brake up) 3 times on each valve to make sure the master cylinder was good. I then decided I'd try to do the whole car (PR, DR, PF, DF), but I just broke off the bleeder valves in the piston, and when trying to extract them broke my ez outs (damn those things never work). So i just re bled the front again and tried to take it out again. Only there were still no brakes. I have no clue what's going on.

Here's a recap of what I all did:
Bled front brakes over 15 times each side
Bled master Cylinder
Swapped Brake booster
Checked brake booster hose for leaks or the check valve not working

The only thing that I think could have caused a problem when we were swapping the brakes over, is that I may have let the reservoir get emptied out when we took the banjo line off the old piston. If that's the case, would the fact I haven't bled the back two brakes in the car really make it completely in capable to stop? The brakes are very resistant when the car is off, but when it turns out I lose all pressure. I've even tried bleeding with the car on. Any ideas would be greatly appreciated!

(Last time the brakes and pistons were used on the old car, they worked fine. The car just sat for about half a year after that before finally being sent over to me so I doubt they'd have gone bad?)