Rustoleum glossy enamel would work , semi-gloss not as well, and the matte not so much. You'll be heavily depending on the primer under it and their primer for rusty metal is a very soft formula that would dig up pretty badly on wheels. Then again, it'll go on, and it'll work, just don't expect good lifespan.
In other words I would clean all the rust off and use a clean metal primer. Whether you can brush it on and be satisfied depends a lot on your brushing skills, but it is a bit difficult to get a good matte finish brushing. Spray would be much easier. To be clear, brush painting matte hides painting mistakes better than glossier paint, but if you are picky about the finish there will be more errors, particularly on something with many holes and curves like a wheel.
Your covers look good, why run without them? I'd just as soon use them and put gloss black rustoleum on the wheels. It will also be much easier to rinse brake dust off of glossy vs matte.
Shorter version: I think you want spray on paint.