The UK style you can find by search for PCL air connector, as it's probably the most commonly used.
Some people do prefer the Euro/German styles (I can't remember their proper names)

I will say if you do go PCL, buy genuine PCL, as there are a lot of cheap copies, that quite frankly are no where near as good, and will fail/ start leaking with little use.

In terms of fittings, nearly all air tool fittings will be some variation of BSP. 1/4, 3/8 and 1/2" depending on the tool. But it may also be described as G1/4, G3/8, or G1/2, which is just BSP with the inch bit dropped, and a G added to magically make it metric.