If you took either to a muffler shop, they can make them fit. There's a difference in length of a couple inches and the transmission bracket is in a different location. A muffler shop could cut out or weld in a section of piping to make the length correct, and either move the bracket or just cut it off entirely (not super necessary anyway, as the midpipe is supported sufficiently by the catback and the downpipe).
Typically custom work like this at a muffler shop is pretty cheap.
Frankly though, if you're thinking of getting a catless racepipe, you might be better served just going to a muffler shop and having them make it from scratch in the first place instead of modifying one of ours. If you're thinking of doing the highflow cat pipe, then it's almost definitely worth it to modify it because we use a REALLY high quality metallic substrate cat and really high quality piping, etc, and at these prices you'd still end up way ahead buying it and having it modified vs trying to get anything comparable from a muffler shop.