Shredso,
Consider using auto premixed can spray paint (its acrylic) for your project don't roll. A caveman can do it!
I get them pre mixed at an auto store to my exact colors and then put in the can. I use a Pantone color book to match the color, you just need a example of the color you want and the store people can mix exactly. Nothing to clever just good eyes. One spray can should do the head with 2 base coats. One can for the special yellow color. While at the store ask them for cheapest suitable can of auto primer and clear gloss to start and finish the project. The spray nozzles on these cans are superb for this work.
Stencils are made a few ways I use clear mylar film 0.5 mil thick from any art store and use a craft scalpel type cutter to cut out the stencils you do the same with the frisket material. Make two, one for each side; one for yellow and one for the black art work. Get craft black acrylic paint from art store to use in your airbrush. I get tacky glue to stick the stencil onto the head. Weekend job.
Steve J