Car destroys clutch slave cylinders???

[brainfood]

So this is the deal, car just went together with a redtop and exedy hyper single. The clutch master and slave were unknown mileage but were working before the swap. Car has nismo pivot point, brand new oe t/o bearing, stainless steel clutch line. Drive the car home from the shop and the clutch works okay but I had to bleed it mulitple times before leaving to get it to work correctly. Get it home and it looses pressure with the clutch in waiting for my gate to open, bam clutch engages and stalls the car. Let the clutch out and start it and it works fine. Move it the next morning and the pedal has no return but is till disengaging/engaging fine. Then later that day no clutch pressure. Look underneath and sure enough the slave is blown all out and leaking fluid everywhere. So I order a rebuilt master and slave from kragen. This is my problem I install everything today and bleed the system about 4-5 times to get the clutch to work correctly also adjust it so it works properly. Clutch is working perfectly. Drive it about a block and back and the clutch pedal starts getting sticky so I let it sit for a second and try to pump it by hand and sure enough almost no pressure (easily pumps by hand) look at the master and it is low so look at the slave and it is leaking. The newly rebuilt slave is leaking?? The new slave doesnt have 3/4 stamped on it like the old one so I am not sure the size might be slightly smaller than the old one. But why would it destroy 2 slave cylinders? All I can imagine is the extra force required to push it the exedy hyper single was too much for them, but what do I do now? Say defective rebuild and go get another one.... order a new oe one from nissan.... or get a nismo slave? I dont want to spend $175 on a nismo slave but after the massive amount of cash put into this car and the fact that it will be a high level competition car it needs to be right. Opinions what to do next? or even why I am destroying slaves?