Truthfully, you can cut down on stuff if you get a double action gravity feed. You can avoid buying bottles and siphon caps and all that, and there won't be a learning curve when you do upgrade to double actionn later. You'll find the cup doesn't interfere with your vision or balance or anything like that. Gravity feeds are much easier to clean in my experience as well, especially since you don't have to clean the siphons or lids or jars. The whole color cup can be cleaned in less than a minute.
You'll need some kind of an air source too, but you don't necessarily have to grab a comressor just yet. You can get an air tank and regulator, and just fill that up at the local gas station. A compressor would be your best bet though. I wouldn't mess with compressed air cans.
You might need an adaptor or two to make sure your hose fits the connections. You'll need stuff to clean the brush with for sure, some paper towels, q-tips, pipe cleaners should work for a while, airbrush cleaning brushes are much better, you can get a great set at DixieArt for about 20 bucks. You'll also need some solvent for cleaning the brush, whatever you use to thin your paints will work just fine, but you'll want more of it.
I guess my list would look like this:
One double action gravity feed airbrush.
One hose.
One air source; tank or compressor.
Cleaning supplies.
Madda
Trifles make perfection, but perfection is no trifle. -- Leonardo Da Vinci
Tact is for those who lack the wit for sarcasm.--maddafinga