I am thinking of gettin some headers for my 99ex.
I have gotten a few interior things off ebay, is it
dangerous to get headers off ebay?? i dont know if i
should trust it...also they say the headers will give you
like 10 hp or so...is this for real and also is there
+/- gas mpg??

As long as its from a reputable brand, and a wholesaler as opposed to a single person. Maybe 5hp across the board and possibly 10 peak if your lucky. 4cyl only has one header. DC is supposed to be good. But I would use the money on something else.

on an Ex, idk if you'll see that much of a gain.

But on the plus side your gas mileage should go up

any difference between ceramic and stainless headers?? also 2 piece and 1 piece??

any difference between ceramic and stainless headers?? also 2 piece and 1 piece??

Ceramic is lighter, but are known to rust out over the years (takes a while) and are also cheaper. Stainless are heavier, but hold up better to wear, will also be a LITTLE harder to dent than a ceramic unit.

As far as one piece and 2 piece, the only advantage to the 2 piece is ease of installation, in all other aspects, the 1 piece is superior.