That looks like an aftermarket catalytic converter, or at least an aftermarket heat shield for it. The bracket you see next to it is normally a brace.
The index markings should be printed on the engine head next to the spark plug holes. The plugs can be found on G1parts for ~$17 each.
Sterling McCall Honda Parts | g1parts.com
Here's my stock catalyst, with the bit that attaches to that bracket circled.
