Do I need to use any sealant or gasket material between the manifold and head?

You'll want a quality header gasket rated for stainless steel to prevent exhaust leaks. Check your swap documentation for the correct gasket type — it's not included with the manifold.

Will this manifold fit my turbo, or do I need an adapter?

The T3 flange is standard, so it bolts directly to any T3 turbine housing. If your turbo uses a different flange pattern, you'll need an adapter.

Can I install this myself, or does it need professional help?

Installation depends on your swap setup and mechanical experience. Expect basic hand tools for mounting; exhaust work and turbo plumbing may require additional labor or specialty tools.