Your best bet is going to be to search online for the part number that you're looking for, call every race shop that shows it as being carried by them, and see if they have any stock left. You probably won't find one from any of the bigger guys like LMR, Summit, Jegs, or CJP, since they've probably sold out of them pretty fast. There is a good chance that you'll find one at a one-off race shop somewhere, but it will take some digging. You might even considder an O/R X pipe as a compromise / backup since those seemed to be more common over the past ten years. Unfortunately, you'll probably end up paying more than you want to, but just let it go and be happy that you found one at all. I've had to do this many times as parts get discontinued or go the way of the dinosaur. The situation for our black-sheep 5.0 cars gets worse every year, with fewer and fewer options for our SN95 specific parts.
If you haven't already, you could call BBK or Brother's Performance to see if any are left.