Need some feedback on a high shot count Condor setup please.

So have not had much luck with finding a 800cc tank that my Condor valve will screw into so I have another idea.

A 4500 psi HPA tank, a 2500 psi regulator, Airforce CO2 adapter.

Curious if this type of setup would yield consistant shots while having a high shot count?

My goal is to drive 18 grain pellets around 1000 fps.

Any comments would be greatly appreciated.

Thanks

Randy