Any of the commonly available spray paints will probably not be too durable. It's just about impossible to match the durability and chemical resistance that a 2 part paint requires. Many spray paints will just dissolve if you get a solvent on them - brake fluid is especially bad on paint. Since mixing the 2 parts in a spray can would result in a can full of hard paint, aerosols don't work for that application. Eastwood makes the Chassis Black in an aerosol, but it's a lot more costly than regular spray paint. It also has to be applied over the right primer. I have used the spray can stuff on some of my parts and it looks just like the stuff that came out of the spray gun. I'm not sure how durable or chemical resistant it is, but it will probably beat any plain old spray bomb.
Eastwood Underhood Black is cheaper than chassis black and would probably work since that is what it is designed for, but it still won't be as durable as a paint that was applied with a spray gun - mainly because of the hardeners and activators that are mixed with the paint just prior to spraying.
'66 Emberglo Coupe - Restoration in progress
5.0 EFI conversion
Rod & Custom Motorsports IFS
TCP subframe connectors
Vintage Air Heat & AC
'99 Black Cobra - Daily driver