Im not using a HVLP gun...actually i tryed going with lower pressure as some suggested, but the paint didnt even want to come out of the gun, so i guess the gun specs were right that the pressure needs to be between 4-5 bars.Try and get one with 1/2" fittings for more flow,especially if you are using a HVLP gun.
You can allways put in adaptors to come down a size but cant very well go the other way.