I was wondering if new headers are worth it on the 05 mustang. If so, is it better to go long or short tube? What are good brands that would mix well with a bassani x-pipe and comp cats with borla stingers?

also does anyone had a bassain x-pipe and borla set up. I was wondering how it sounds.

 

If you are working with a GT, short tube headers are not worth the money. The stock Ford exhuast manifolds are pretty good. Installing shorty headers and leaving the cats in place will only get you maybe 10 hp. However if you remove the cats and install long tubes you should gain around 20 - 25 hp.
V6 is a different story. The stock V6 exhaust isn't nearly as good as it is on the GT so on a V6 shorty headers would be worth it.