Keyboard Shortcut for "Save a Copy > PNG"

I'm going nuts here trying to solve what should be an easy problem and I'm stuck.  I want to have a keyboard shortcut (ideally Ctrl+Shift+P) that could automatically run File > Save a Copy > PNG.

I've tried two methods that each get me about 90% of the way there, but ultimately don't work:

1) Create a shortcut for Quick Export as PNG.  This creates a PNG image, but it increases the bit depth from 24 to 32, which makes a larger file size (but same quality since the original is 24).

2) Make an Action with a function key shortcut for File > Save a Copy > PNG.  This creates a PNG image with the correct bit depth, but does not prompt for a file name and overwrites any existing image with the same name, so that won't work either.

Is there a way to do this, or do I just have to enlessly punch through files names to get a PNG every time I save?