Any Home center should have one that looks like this.
If all they have is male then just add a coupling.
http://www.homebrewing.org/12-FPT-x...LDBBRC8oICb9NvKsg0SJAD9yOHsQFSET33xR0x1DXMo8u6_jbE46qjEV2O2eStsoAeYehoCZ5fw_wcB

 

I need sort of the reverse of that adapter. Where the female pipe threads are in that adapter, I need those to mate with compression threads and have the "top" be pipe threads (NPT) so I can plumb to the pump using standard pipe.

 

Maybe this would work for you. Your check valve /w compression then copper to a compression/pipe adapter, then pipe to where ever you need it.

 

I think that would do it! Where can I buy those?

 

You really need to plumb the compressor pump to the check valve with tubing and not solid with threaded pipe. This is often done using copper tubing for better heat transfer to help cool the compressed air but more importantly to offer some vibration dampening. The tubing is normally routed so it has a loop or a few oversized bends to allow some movement. Plumbed solid with threaded pipe the vibrations will likely crack the pipe at the threads or worse yet the compressor itself. You can easily find the correct compression fitting to either male or female pipe thread to screw into the compressor pump, then you will be able to connect the compression fitting in the pump to the compression fitting on the tank check valve with tubing.

 

I'll be using something similar to this so it's not rigid although it is NPT pipe thread

https://www.grainger.com/product/HOSE-MASTER-Flexible-Metal-Hose-2ZV57