first off, is it the dohc VTEC (no H) or the sohc vtec? If it's the dohc b16, it's the PERFECT engine to build up. The b18c5 would be pointless with what you ahve already.

AEM is one of the most reputable companies for intakes. You probably have close to a $200 intake on there.

You asked about an exhaust manifold... You already have a dc header, again a great piece, that's worth a nice chunk of change. If the exhaust hasn't been upgraded, get a cat back system.

The rest I'll leave up to others to help. Gotta run!