I got a Greddy header second hand from a honda-challenge car that someone on hybrid.jp had for 100 bucks. It was tarnished, but none of the welds needed rewelded. Pretty thick gauge tubing, large 1 5/8" primaries, rather abrupt merge from 4-2, and a decent merge from 2-1, with a 2" collector. I really like it because of the overall powerband increase over stock.
Drivability is nice, with a decent top end. A larger collector should prove better for higher rpm use, but I'll leave it as it is. I wrapped it with thermotec header wrap, and that's the way it's been for 2 years now. One thing I would suggest is to find some high temp gasket material(the kind you cut out, not silicone gasket maker or anything...) and cut out a new 4-2 flange gasket. Mine was pretty shot when I got it, and now I have a gasket from a different aftermarket manufacturer on there.
Hope this helps.
-josh-