i bought two header kits from jegs, they were 129 each kit. I got 2 1/8 and 2 1/4. Then i bought the pre welded flanges. I made a pretty nice set of step headers for my car and it was under 400.00 for all the parts. Check out the Jegs kits. You prob only need one kit since your not going under chassis with them. You have to make the collector, i used my friend muffler machine and slip flanged 4 pieces of tubing and used the lil tabs to bolt them on. So i made my own slip on collectors.
spd out of california has good tubing... and they got 2 3/8 16 and 18 guage.... i found it kind of hard finding a assortmant of radiuses... there the only ones that carry the tight bend of 3" radius... and i got my flanges from kooks