what headers to use?

Hey yall give me alittle advice please. My headers are shot and I need new ones, help me chose. My car is a bracket only car, 408 stock heads 2.02 with home porting but not flow benched but I feel they work real well as I have ported a dozen or so sbm heads, flat top 11 to 1, steel crank, .568 solid lift cam, 4200 stall, 4.88 gear, 31x 10.5 w slicks, victor jr, 830 hp. I run one chamber flows (mufflers are optional but requested at our track) and the inner fenders are gone. The car is 2800lb with me in it. 6.66 in 1/8 1.40 short times shifted at 6500 in best conditions. I currently have cheap 1 5/8" headers with 3" collectors. Header coating is not a concern nor is chassis or fender exits. I would speed the 600 or so for bigger primary headers if I thought it would help my combo. I have never run large tube headers. Should I stick with cheap small tube headers or spend the bucks on bigger ones, where is a good place to find them. Thanks for any suggestions, Ray