I've fitted the Holden booster. The issue I had was that the plunger rod is not held in with a circlip (bugger) but is fitted prior to the booster halves being joined. It required that I have a specialist split the booster and remove the plunger so I could shorten it and machine a thread. I then had to have a specialist refit the rod and rejoin the booster. If I recall it was only $20 + $20.
I'm not sure on the exact details but there is something about the reservoir on the M/C has to at least match the piston capacities of the brakes. I'm running Wilwoods and the Holdem M/C just makes it. Someone may need to clarify this point.