Good n2 tank reg??

[Dustinshell]

So I was going to get a Crossfire 88ci 4500psi Phat High Pressure Fixed Nitrogen System 800 psi output. Should I get a tank reg or run it through an asa and into the inline reg which comes with the Speed? And if I do need a tank reg which should I get? I nitro duck, thor, etc...

[Dustinshell]

"The reg is set to take low pressure input it can be re sprung for HP gas, but best performance is from about 450 to 500 psi going into the mini reg."

Is this true?? If so would it be smart of me to get the Crossfire 88ci 4500psi Phat High Pressure Fixed Nitrogen System 800 psi output and get a thor and set it to 450 psi output?? I know the thor can do 300-600 psi. Can the thor bring the 800 psi from the preset tank to 450? It says 300 - 600 and the preset is 800. Does this mean the tank has to have an output of less than 600 to start with?