Can anyone recommend one please. The one I have from Halfords sends about half the air into the tyre and the other half out the sides of the valve/inflator.

I’ve seen a flash Park one but I don’t want to spend that kind of money.

Mine is just some bit of rubbish that came with the compressor, works fine tbh. I chopped the original valve off and fitted a 2-way one for presta/schrader though. (£2 from Decathlon)

I had a air tool shop near me make up a length of hose with a Presta trck adapter on one end and a lever valve on the other with the correct connectors, great for tubeless, no pressure gauge though.

I may try ad concoct something from an old track pump

Prestaflator now in the uk here ->
http://www.nextdaytyres.co.uk/prestaflator