Power Brake Hell..... HELP!!!

not sure by what you mean by "spongy".
-you can't lock the fronts no matter what, even with the peddle bottomed out, but not touching the floor?
-because the rears lock up first, (they will with a stock portioning valve), you've never gotten into the peddle far enough to lock the fronts?
-no matter how hard you push, the peddle keeps going down, the fronts never lock, and the floor is the only thing stopping it?

personally i hate power brakes on A-bodys. you might want to at least try it without the booster and see if it improves the feel.
also, like was stated, you need to do a propper bench bleed on the MS.

good luck

edit: the KH brakes work fine if everything is in good shape