Isn't 46lbs injectors overkill?
When you mention a boost controler, you mean some sort of a valve inside the car to lower boost when cruising?
At 12psi, are you running on stock HG? simply with a good tuning? that's pretty good 
I thought 9 psi was the line not to cross, but maybe the MS is helping a bit
46lbs as boostede30 says is good for my boost level. With the MS in there I still get decent mileage as well. LOL on my last trip to Houston I got close to 40mpg, better than before the turbo.
The boost controller is a solenoid that increases the boost and stabilizes it by limiting the pressure your wastegate actuator sees. For example I have my actuator set to 7psi... if I set the controller to 12psi it will make the pressure the actuator sees at 12psi equal to that of what it used to see before the controller was put in (7psi). There are manual ones and electric ones... you can even control it with megasquirt, which I am trying to work out now.
I am running stock head gasket. With the boost controller I am going to do 12psi up to 5000rpms and then drop down to 10psi to redline in an attempt to have the head gasket last longer. But I think it's only a matter of time before I have to do a new one with o ring'd head and ARP studs.