Custom exhaust questions/comments

Hi all, I am new to this site and have an Armada. I am very interested in an exhaust for my new ride and have tried searching to see what everyone here likes as far as exhaust goes. I really like the flowmaster sound but I only want one side exit. I called Billy Boat exhaust to see if they make a system for the Armada but they dont plan on building one. I really like the way their exhaust goes two pipes into the muffler (eliminating the y-pipe all together). http://www.bbtriflo.com/B&BMain.htm So give me some comments on this: Flowmaster 70 duel in/single stock exhaust out. I am just curious why none of the other exhaust manufactures have gone that route and if you guys think it is a viable option.