Permatex Ultra-Black Sealer

Only a very small amount of sealer is required around each exhaust port. An entire tube of Permatex is more than enough for a complete engine build, where sealer is required at intake manifold gaskets and many other locations. Example:
https://centuryperformance.freshdesk.com/support/solutions/articles/17000029622-basic-header-installation-procedure

If I'm understanding the translation properly, you are asking whether or not to use a composite gasket or silicone gasket maker between the cylinder head and the exhaust headers. DO NOT use a gasket at this location. Only use a ~3.175 mm wide bead (smear) of silicone around each exhaust port opening, let it dry, and then install the headers.

Si je comprends bien la traduction, vous demandez s'il faut ou non utiliser un joint composite ou un joint silicone entre la culasse et les collecteurs d'échappement. N'utilisez PAS de joint composite à cet endroit. N'utilisez qu'une perle de silicone d'environ 3,175 mm de large (frottis) autour de chaque ouverture de l'orifice d'échappement, laissez-la sécher, puis installez les collecteurs.

Use what you want?! Black works and is recommended. Copper also works. This question has been answered before. Remember, you're not actually creating a gasket. The silicone is merely providing a seal for minor machining variations and thermal expansion/contraction.

The cylinder head gasket and exhaust gasket are two VERY different applications. Please follow the installation instructions provided with the headers.

Correct.