I prefer the original Stencil Genie as a holder, as it is simpler than another notable brand out there (fewer parts) and works just fine for me. As for airbrush brands, I use different ones for different things: Spectrum Flow White because it's alcohol-based and dries more quickly than other whites; AmeriMist (aka AmeriColor) for lots of other colors (they have the broadest color range); and Chefmaster for certain other colors (particularly their Harvest Brown).
There is more to airbrushing and stenciling than many people think. But I have many good videos about my stencil line, and I cover good airbrushing technique in nearly every one. You may want to check them out.
Happy stenciling and airbrushing!