For any of the Hot side parts - jpipe, downpipe, turbine housing, exhaust manifolds, exhaust manifold heat shields - if going with the Cerakote brand we have had good results with the V and Glacier Series. If you go to their website and filter by temp choose 1800F. Also note you do not want to choose any of the colors that fall under their “High Thermal Emissivity” filter. That’s bad, we’re trying to keep heat in, not radiate it. The “low thermal emissivity” are the best about not radiating heat but come in odd colors
Cold side parts - I think pretty much any of the Cerakote colors would stand up, some are better than others for being a thermal barrier. For the most part any cold side parts being coated are for vanity