Be warned that spray painting is more than just a skill, it is an art.
You will need to practice before you attempt to paint that cowl. There
are numerous paint guns available. Try Northern Tool. They have
numerous outlets and a web site. You will need a device to separate
atmospheric water from the compressed air, also.
Also, the regs require weighing and rebalancing control surfaces.
( a bunch of )
So be cautious what you tell your mechanic at the next annual..
Again, Imron is dangerous stuff. Had a pilot at the field sent to
the hospital for two weeks for not using an aspirator while spraying in
a hanger. It can be absorbed through the skin and disrupt the nervous
system. Almost as bad a nerve gas.
Dupont has a second tier product paint, Chromacolor, a binary paint
which is typically used on autos. I do not have any experience with
this product.