You don't need an unloader unless you're using shutoff guns. With a weep gun you want a balanced pressure regulator. Try the SMC 555 series 2000-2000 PSI range.
I prefer the Giant 22911 up to 13gpm up and 1400 psi, if more pressure is needed the then the 22913 up to 3000psi . A little pricier but they work for years and are rebuildable