not that hard to do it yourself.. for small # of firearms.
blasting cabinet.
a good dry air compressor
HF air brush
heat box ( build your own ) I built one out of wood with foam reflective insulation... and use a $10 HF heat gun. Easily gets to 300 degrees and works like a champ. google heat box and you should find many home made styles
some things are just fun to do yourself
I find ceracoat the easiest of all two part paints to use.. goes on dead smooth