Do I need new gaskets when I install this header?

You should grab fresh exhaust gaskets to seal the flange connection. Factory gaskets can compress and leak once you disturb the joint—new ones prevent exhaust leaks at the manifold interface.

Will this header fit with my stock exhaust system?

It bolts to factory mounting points, so it'll connect to whatever exhaust you have downstream. Just confirm your mid-pipe or catback doesn't interfere with the header collector—some aftermarket exhausts have tighter clearances than stock.

Does this need to be painted or ceramic-coated before install?

Stainless steel doesn't rust bare, so you can install it as-is. If you want a finished appearance or thermal protection, ceramic coating or high-temp paint can be applied beforehand—but it's not required for function or durability.