I'd recommend avoiding the mini KMs and going with one of their larger models. Actually, try to avoid any Egyptian mini if you can get a larger one.
The Amer is not a brass hookah. They are hollow stainless steel. There are also multiple versions of the stem, each with slight variances (3 that I've come across). If you want the OG Amer with the brass ring shank with KM stamping and the original hose tube with engraving, get it from Hookah Company. The same is true for the OG Butterfly and Hafa. If those details don't matter to you, the other variances are so minor it won't really make a difference where you get it from.