i agree with milltek, i use a milltek corrado g60 downpipe with my exhaust manifold proted to match, then milltek centre sections mated up to speedtech rear boxes, but chances are i'll go for the remaining milltek system when money is less tight. i've heard of so many stainless 4-2-1 manifolds cracking, which is why i went for the miltek option. i went for a piper cam, can't quite remember why i chose this over kent. air filters, any performance one really, k&n, jetex response, don't like the foam piper ones though.