Aftermarket muffler Question.

If I get a custom exhaust set up do I have to go with the stock horizantal looking muffler or can I get a fireball style. The guy at the muffler shop in town said he put a horizantal looking one on but I spaced to ask him if he could do one like a fireball style, and his shop isn’t open today so thats why i’m posting.
Replies appreciated.

You can se what ever style exhaust cannister you want.