I'm pretty sure Ninja sells adjustable pressure kits though, which you could use to raise the output of your reg.
Etek 3LT grey/black f/s
Valken Proton greyish/black f/s
68 4500 PE stubby, LP output f/s
68 4500 AIR tank(no reg) f/s
Creed Battery, eyes and noid f/s