HVLP does use a considerable volume of air, and something you need to weigh out in looking at paint guns. PSI is much less of a consideration, how quickly your compressor recovers is. Will your air compressor support it? Just to show a comparison, a SATAjet 500 has a CFM consumption of 15.2, an Iwata LPH-400 has a CFM consumption of 8.3 so you need to first determine what you have besides a name brand to see if it even has enough CFM to operate a paint gun efficiently. Then you can shop around based on what your air compressor will handle, or perhaps you will need a new compressor as well.
