SBC stepped headers for 23 T

Hi everyone, newbie over here.

Im from New Zealand and am currently looking for some new pipes for my 23 T Bucket.

Its running a pretty healthy SBC 350 that has 420Hp naturally aspirated, also runs a nitrous works magnum x bar 2 stage system. Has a turbo 350 with trans brake, 5000rpm convertor and Ford 9 inch with 4 spider LSD and 4.11 gears.

My bucket is used on the drag strip, and is street registered and driven, but only to the shops and short rod cruises etc, fule cell only holds 40 litres.

Still a street engine as its got a hydraulic roller cam, admitadly a reasonable sized one with 600 lift, also forged weisco pistons, eagle H beam rods, roller rockers, stud girdle, 4 bolt block, grout filled, well 1/2 filled. Team G manifold with holley 650DP, alloy Dart pro 1 heads with stainless 2.02 and 1.6 valves, all rocker gear is comp cams

MSD digital 6 plus and 2 step reatrd for the nitrous.

has run a 10.2 @ 133Mph naturally aspirated and was orginally built as a street rod that would occasionallly see the strip, over time has tunred into a strip rod that occasionally see's the street.

anyway to the point of this thread, the headers were orginally built as just rod headers, now that Im chasing more and more performance, i want to go to a steeped set of headers 1 & 7/8's to 2 inch, that would be maybe a bolt up fit for a T bucket. also after some merge collectors to suit.

could anyone point me in the direction of a good exhaust shop over in the US, or any aftermarket supplier that could do this off the shelve.

I have access to good shipping rates and have a jegs and summit catalog but can't find what Im after in there.

Thanks

Allan