Ok, I have searched and searched and these were the only products I could find for a 2003 LS (4 door) 2WD Blazer:

Headers:
JBA

Cat-back exhaust:
Dynomax Super Turbo

and that's it... Of all the exhaust companies I have one choice for headers and only one choice for exhaust. That's it.

Correct me if I'm wrong...

I had the same problem when I was looking for an exhaust. I just had a Flowmaster 40 Series put on in place of the stock muffler. I really like the way that it sounds and it was inexpensive. I can't help you with the headers as I didn't look for them.

I posted a bunch of info under your other post about piping diameter. Didnt see this one until after.