I have seen an advertisement for pacesetter headers in some of the magazines. They are pretty cheap and the performance gain is questionable. Maybe someone else who has used them can provide some information on those.
Nissan motorsports use to make an awesome polished race header that wrapped around the side of the engine for groud clearence. However, i bought the last set of those abot four years ago and have since sold it to a B11 guy. If you could get your hands on it, it's one beautiful piece of work.
As far as intakes are concerned, I believe all they have are the drop in round K&n filter elements. You may be able to modify it a bit by getto rigging the filter cover so that it is more of an open elelment. I beleive John Nismodriver had an intake custom made at one point. That is also a possible alternative.