To add to the confusion some of the many fittings have cross compatibility as well.
I had a most confusing spreadsheet I found listing almost every combination.

I recently added a hardline air system and decided to make everything PCL XF quick connectors ( my kremlin sprayer requires the extra flow rate anyway) for simplicitys sake.

A quick note that coupling prices vary a great deal, one place might be cheaper on male 1/2 inch but more expensive for femele 1/4 inch no idea why.
Machine mart are quite expensive (but convenient) , also screwfix. I found cotswold engineering the cheapest overall for my total order.

Ollie