Dream Marauder?

I've done a lot of experimenting on my .22 Marauder. It's my basic test platform before I do anything to my .25 marauder now. However I've always wondered just what I could really do to this rifle to make it the best it'd ever be. Of course there is one little problem my little list that follows faces.

Marmot Militia barrel
jdsairman B-rod Adapter
Cut down air tube
jdsairman 4500psi reg
Talon tunes 480cc 250bar bottle

Not sure how two regulators would function with one another since I currently use a Huma gauge block version and would like to keep it that way, and if I did have to use the jdsairman by itself I'm uncertain of exactly how I'd set the pressure and test it.