What else do I need with this because in the pictures they look misleading...Will the downpipe reach to the cat or do I need to weld another piece of pipe into it? Or am I over thinking it and it just fits right on?

 

It replaces the factory exhaust manifold and down pipe. And then after about 30K miles the weld between primary 1 and 3 will crack wide open.
If you really want to use the header, make sure to warranty it before the warranty is up. IMO, if the exhaust manifold and pipe are not damaged, don't bother with the header.

 

Well I have a cheap ebay one that has hit the fan

 

just stay oem dc sports headers are junk

 

Where can I ind the OEM A6 manifold and downpipe

 

the junkyard, ebay, or rockauto