Do I need new gaskets and bolts to install this?

Yes — use new header gaskets and OEM-spec fasteners. Don't reuse old gaskets; they won't seal properly on a new header flange. Torque specs are in your factory service manual.

Will this header work with my stock exhaust manifold gasket?

No. Header flange gaskets are a wear item and must be replaced during installation. Buy new ones before you start the job.

Does this need to be ceramic coated or painted?

Stainless steel doesn't require coating for corrosion protection, but some builders ceramic coat headers for heat management. That's optional and a separate process done after installation confirms proper fit.