Any opinions on what the best 'aesthetic-coating' for an exhaust manifold is?

Are these manifold paints any good?

Is powder-coat an option?

Try powdercoat, that will give you good smoke for a short time.
I had a V8 manifold coated in the US a few years back. That was ceramic coating. I was quite impressed with the way it holds the heat inside the pipe.

Søren S2
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After coating.
Here is has done several hours of racing.
Notice tha stainless stell trumpets wich is not coated. They have that hot colour.

Søren S2
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Spray on Zinc Rich primer burns off to leave a nice white coating on the exhaust manifold (fumes prob toxic) --- last longer than most exhaust coatings.

Normal stove-enameling powder coating won't last long --- somehow Jaguar got it to work on the pre 1970's XK engines but I haven't seen any body else make it last.

Sperex type VHT coatings works great on tail pipes and lasts for while on manifolds.

Chrome plating is another option but it has its own problems.

Cheers!

Cermachrome - Head manifold, spray on, gentle heat to dry off then play blowtorch on for 5 minutes, cool and buff up with scotchbrite. Near indestructable finish and can be applied to the insides of the pipes as well.