I completely forgot about those Tamiya jars. Don't have any but saw them on Tamiya's site a while back. If you can get them they'd be ideal. Graduations to give you a visual for mixing, plastic cap liners that are pointed for the paint to run down instead of pooling in the top, wide mouth for filling and stirring. Don't get much better. Unless of course they would screw on an airbrush cap.
Personally, I've just reused bottles I've emptied and airbrush bottles. I have a bunch of empty 1oz Plasti-Kote Touch Up bottles. That's my favorite primer.
Tony