why a custom built converter isn't for everyone....

That could work out in your favor. Boss Hog converters have a real shitty reputation for being loose. If they said you need the next one up, then you might be right on the money with what you have. There sure are better converters out there. Those things are for the Chevy boys so they can say they have a stall. They love those things. As always, make something with a cool name and all the Chevy guys will jump all over it.
Thats funny because my machinist recommended me the boss and he is a Chevy guy hahaha